Just completely failed smog at 15mph
#1
Just completely failed smog at 15mph
Not sure if this is the right section to post, but I just failed my smog test today at 15mph. The HC max is 66 and I read a 116 and the NO max is 487 and I read at 2591. I just got the car less than a week ago and so far just sea foamed the car through the brake booster vacuum. Iwas told at the place that smogged my car to check the egr valve, but i don't have 1 on this car
After I failed, I sea foamed the car again (Brake Booster line x2 total), replaced spark plugs, wires and distributor cap and rotor that looked worn out. Opened the valve cover and no build up. Put in a bottle of fuel system cleaner in my tank, so I have to run it down close to E before another test.
I'm thinking if it's the purge valve, or pcv valve or the cat or o2 sensor or sensors, since the car's mpg seems a lot lower than it should be. Also does the rear o2 sensor do anything more than just reading and sending a signal to the ecu that the cat is functioning?
The reason I failed: The guy said the car wasn't burning fuel. Car has 173,xxx miles.
ONLY mods are a AEM carb legal short ram arm intake and carb legal 2 piece pace setter headers.
Any suggestions where to start? I'm in California and trying to complete my smog to finish my transfer of sale registration.
TIA
1998 HONDA CIVIC EX EJ8 COUPE
After I failed, I sea foamed the car again (Brake Booster line x2 total), replaced spark plugs, wires and distributor cap and rotor that looked worn out. Opened the valve cover and no build up. Put in a bottle of fuel system cleaner in my tank, so I have to run it down close to E before another test.
I'm thinking if it's the purge valve, or pcv valve or the cat or o2 sensor or sensors, since the car's mpg seems a lot lower than it should be. Also does the rear o2 sensor do anything more than just reading and sending a signal to the ecu that the cat is functioning?
The reason I failed: The guy said the car wasn't burning fuel. Car has 173,xxx miles.
ONLY mods are a AEM carb legal short ram arm intake and carb legal 2 piece pace setter headers.
Any suggestions where to start? I'm in California and trying to complete my smog to finish my transfer of sale registration.
TIA
1998 HONDA CIVIC EX EJ8 COUPE
#2
Re: Just completely failed smog at 15mph
There is a few things to do, first off, did you get the car fully warm before going to emissions? Drive on the highway for 20 minutes then go to your smog place. When in line hold the rpm to 2K until you get in, that keeps the Catalytic Converter hot. It will not do it's job when cold.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
#4
Re: Just completely failed smog at 15mph
There is a few things to do, first off, did you get the car fully warm before going to emissions? Drive on the highway for 20 minutes then go to your smog place. When in line hold the rpm to 2K until you get in, that keeps the Catalytic Converter hot. It will not do it's job when cold.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
#6
Re: Just completely failed smog at 15mph
This plays a huge role in the test, the cat cooled off so it couldn't burn the fuel into CO2 and water vapor.
RonJ@HT gave you the best advise. Which I believe you already did but after you failed, solid tune up with NGK wires and plugs aka OEM. And go again. This time keep your cat hot while you wait. A cold cat does nothing.
If your cat was failing it would be throwing a P0420 code which your emissions guy would or should have told you.
RonJ@HT gave you the best advise. Which I believe you already did but after you failed, solid tune up with NGK wires and plugs aka OEM. And go again. This time keep your cat hot while you wait. A cold cat does nothing.
If your cat was failing it would be throwing a P0420 code which your emissions guy would or should have told you.
#7
Re: Just completely failed smog at 15mph
There is a few things to do, first off, did you get the car fully warm before going to emissions? Drive on the highway for 20 minutes then go to your smog place. When in line hold the rpm to 2K until you get in, that keeps the Catalytic Converter hot. It will not do it's job when cold.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
I put guarantee 2 pass last night. Now after plugs wires cap and rotor car is fuel efficient and can't burn the tank down fast enough to do smog for awhile.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
Have you done a compression test to see if your rings are in decent shape, if the compression is at the bottom end of spec, it will be harder to pass.
Not sure if they have it in the states but you can also try, Guaranteed to Pass additive. It's rather hard on the car so they say only do it once a year at most.
You did a tune up so that will help too.
If you have two O2 sensors I would think you would have an EGR valve but you didn't post year make of car or what motor you have so no way to verify.
I put guarantee 2 pass last night. Now after plugs wires cap and rotor car is fuel efficient and can't burn the tank down fast enough to do smog for awhile.
The typical spots for high NOX is EGR problems, you say you don't have an EGR system. Advanced Ignition Timing, you did a tune up so should have set the ignition timing, a little retard might help reduce NOX, so that should be ruled out, then there is the three way catalytic converter, if it's bad you will get high NOX. And lastly, combustion chamber deposits but you seafoamed the car twice so that should help with the combustion chamber. I personally enjoy the Italian Tune Up method to burn out deposits but finding safe places to do that is not so easy.
Really, other than a bad cat, I think you've covered most of the areas that cause bad NOX reading for the car so should be in decent shape for your next test.
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#8
Re: Just completely failed smog at 15mph
took 5 minutes to find your reply. you stuck in the quote of my reply.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
#9
Re: Just completely failed smog at 15mph
took 5 minutes to find your reply. you stuck in the quote of my reply.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
#10
Re: Just completely failed smog at 15mph
took 5 minutes to find your reply. you stuck in the quote of my reply.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
follow the directions of guaranteed to pass to the letter. don't go to smog with it in the fuel.
Also, you said you added a fuel injection cleaner, did you get through that tank of gas first before you added the guaranteed to pass? probably not the best thing to have both additives in one tank of gas. If not too late now, so burn that full tank of gas, refill up, drive at least an 1/8th of the tank then go for smog. if you aren't legal to drive ie no permit or plate then you can idle the car all day until the tank is near empty. will take awhile but can be done without driving.
#11
Re: Just completely failed smog at 15mph
No guarantee to pass is the 1st and only fuel additive in the tank. After getting the oil change, 1st o2 sensor and pcv valve and plugs wires cap and rotor the car is getting way better gas mileage Im having a hard time running the gas out when before a little less than a 1/2 a tank was on 70 miles now I got 110 with about 1/8 th a tank and trying to burn gas. Hopefully it means it's all fixed now?
But it's in now so might as well follow through, can't do smog with the additive still in the tank. Have to finish that tank of gas then refill, then do smog.
#12
Re: Just completely failed smog at 15mph
Yeah, jsut like Ron stated, do a full tune up and you should have no issues with smog. The can of Guaranteed to pass was probably a waste of money and uneccessary strain on your motor. It's one of those last resort sort of things. Was suggesting it for a case of you failing a second time after doing a full tune up.
But it's in now so might as well follow through, can't do smog with the additive still in the tank. Have to finish that tank of gas then refill, then do smog.
But it's in now so might as well follow through, can't do smog with the additive still in the tank. Have to finish that tank of gas then refill, then do smog.
I replaced:
spark plugs
spark plug wires
distributor cap
rotor
1st o2 sensor
pcv valve
oil change
checked the purge valve (holds pressure no leak)
Going to clean my AEM dry flow filter with the proper solution later today.
Fixed exhaust leak before my 1st smog
Just waiting to burn this tank of gas and get the cleaner out.
#14
Re: Just completely failed smog at 15mph
Thanks, just did the valve adjustment and ignition timing, and cleaned the filter today with dry filter cleaner, just need to burn a couple gallons more.
Should that be it?
Only thing I didn't replace or check was the rear 02, timing belt, and I think the cat is still good?
Should that be it?
Only thing I didn't replace or check was the rear 02, timing belt, and I think the cat is still good?
#15
Honda-Tech Member
Re: Just completely failed smog at 15mph
You have in increase in all poor-combustion related elements. Your O2 was higher, CO, and NOX, NOX is the odd-duck here. Since your combustion efficiency at the "tailpipe" is higher at 25mph, The only thing that can produce NOx at those levels with a decrease in combustion at 15mph is a failed converter. Has the converter ever been replaced before?
I would compression test it just for the sake of diagnostics.
I would compression test it just for the sake of diagnostics.
#16
Re: Just completely failed smog at 15mph
You have in increase in all poor-combustion related elements. Your O2 was higher, CO, and NOX, NOX is the odd-duck here. Since your combustion efficiency at the "tailpipe" is higher at 25mph, The only thing that can produce NOx at those levels with a decrease in combustion at 15mph is a failed converter. Has the converter ever been replaced before?
I would compression test it just for the sake of diagnostics.
I would compression test it just for the sake of diagnostics.
Do you think it's still the cat failing?
#17
Honda-Tech Member
iTrader: (3)
Re: Just completely failed smog at 15mph
Not sure if the cat was ever replaced? But, I didn't drive the car enough before trying to smog it, all the parts were carb legal and I sea foamed it 2 days before, and it drove fine with no hesitation or stalling and the rpms are normal, but later found the mpg to be horrible. Now the mpg is way up. They told me the car wasn't burning fuel, and I found the plugs, wires and cap, and rotor were bad, the pcv valve was done and the the primary o2 wasn't even hot after a 40-50 min drive, but replaced all of it. But, I didn't see the smog tech use a sniffer, just seen him plug in the scan tool.
Do you think it's still the cat failing?
Do you think it's still the cat failing?
how did you seafoam it?
Details
#18
Re: Just completely failed smog at 15mph
Sea foam through the brake booster line.
After Sea foam:
spark plugs
spark plug wires
distributor cap
rotor
1st o2 sensor
pcv valve
oil change
checked the purge valve (holds pressure no leak)
valve adjustment
ignition timing
cleaned my air filter with the right cleaning spray
Used guarantee to pass in the tank filled up (still have to burn 2-3 gallons more before adding gas)
Fixed exhaust leak before my 1st smog
EDIT: The coolant tank was missing when I got the car and the hose was tied off. Went to the junk yard and got the reservoir and filled with coolant to make sure there's no air pockets getting in. Did this after I failed. (Car never overheated/Radiator had full coolant)
After Sea foam:
spark plugs
spark plug wires
distributor cap
rotor
1st o2 sensor
pcv valve
oil change
checked the purge valve (holds pressure no leak)
valve adjustment
ignition timing
cleaned my air filter with the right cleaning spray
Used guarantee to pass in the tank filled up (still have to burn 2-3 gallons more before adding gas)
Fixed exhaust leak before my 1st smog
EDIT: The coolant tank was missing when I got the car and the hose was tied off. Went to the junk yard and got the reservoir and filled with coolant to make sure there's no air pockets getting in. Did this after I failed. (Car never overheated/Radiator had full coolant)
Last edited by tayone415; 01-22-2014 at 11:24 AM. Reason: Add Detail
#19
Re: Just completely failed smog at 15mph
You should pass without issue. The biggest help is to keep the cat hot while you wait in line. Turning the car off for 30 minutes before the test lets the cat get cold and then it won't do it's job properly or fully or as efficiently.
#20
Re: Just completely failed smog at 15mph
I know, I was going to try to ask if I could just wait in my car with the motor on, when I went there for the smog it was 1st come 1st serve, no appointments and on a Saturday, so I took my chances, and it was already a gamble with passing. But, thanks.
#21
Re: Just completely failed smog at 15mph
I passed today after the 2nd time, 3rd time and 2 smog shops later, my cat all of a sudden got plugged up, but got a good deal on a magnaflow cat w/install and changed the fuel filter, and everything read way below the max except the NOx was under max by 2. The smog tech said it was because of the aftermarket headers.
#22
Re: Just completely failed smog at 15mph
NOx will not go down if there is a very small air leak right before the cat. NOx will not be reduce when you have a lot of oxygen present. Fix your leak in the exhaust system before the cat and it will drastically lower your NOx emissions.
#23
Re: Just completely failed smog at 15mph
I had a leak pre cat but, I already had that fixed, Nox was only close to max at 15mph, but the cat was still brand new with less than 5 miles on it, the extra oxygen would be from the air intake and headers, the guy said people usually fail from performance headers. But, oh well I passed, I don't have to care for 2 years now.
Now to get my other car ready or just pay to pass smog.
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