so i took my stock 96 civic to smog on Monday and failed smog tech recomended to change air filter, spark plugs and wires.. it failed by a little so he said maybe doing that will help since there's no CEL .. i decided to buy NGK spark plugs and went to Autozone and asked for spark plugs Autozone gave me "Platinum" , checked all gaps (0.40) car started and everything was ok , took the car to smog the day after and IT GOT WORST !!! so been reading and they said to use cooper spark plugs , clean throttle , iacv, and run 89 gas ... Question is could the cause of getting worst be the fact that I used Platinum spark plugs ?

 

1st pic is the first time it failed , 2nd pic got worst

 

have you also tried to do a full tune up like cap rotor and plugs and filters and i have been using plat plugs in mine and it seems to b e doing fine passed em issions with flying colors

 

i have seen cars pass with plugs that you wouldn't think would even spark . if your plugs where bad and you put in the new ones they could be burning off the deposits from the cly making your readings worse . i would check you o2 sensors just because the cel isn't on doesn't mean it's working well.

 

looks like your running rich somehow...high CO and HC mean your running rich or not burning all the gas but yes go with NGK coppers/ v power . but second pic looks like your "cat" is messed up because the NO/CO/HC are all above and high. those y7s use steel inside the cat and they wear out fast.

 

Failed so little? What? your car shouldn't even BE at those levels.. You need a major tune-up/service. Look at the maintenance schedule in the owners manual and do every single thing. Things that it won't mention but you should do are repairing/cleaning EVERY!!! electrical ground in the engine bay, including the battery's negative cable, and not inspecting but replacing the PCV valve, clean IACV, etc. If you can, get a multimeter/ohm meter and measure the ohms value of each ground to the battery ground cable. If it's above 1ohm, you should clean/repair the grounds.


Btw, if you replace parts, use OEM only parts. If they suggest bosch, PASS on it! Stick with NGK and DENSO if you want to be headache free.

 

Mine was pretty bad also but after Bosch IR fusion(platinum iridium with 4 contact points) plugs cap rotor wires o2 oil change and a fuel sys cleanser I was doin real well. Also get the motor real hot and run it for a good amount of time before the test. Hit those Honda Rpms and unclog those injectors from that watered down arco gas and u should be in good shape

 

I guess fleabag didn't have good luck with Bosch parts. I've tried them all and actually had the best performance with the IR fusions. Over ngk irids. It's my dd and still running 200k strong

 

won't believe it until I see your smog report.

 

Did you leave your car running while you waited or did you turn it off. The Cat needs to be hot in order to work properly. Run the car down the freeway for 5 or 10 miles and leave it running while at the shop before the check. Try this along with a full tuneup and oil change.

 

how is running the car hotter gonna make him pass smog if his cat is possibly bad???



bosch iridiums 4 prongs? lol i used to think those things helped. but i learned

 

ok so I FAILED again , we just did a quick test before sending data and numbers still high , for some reason. the forst time i failed it was pretty close to pass and now numbers are in the ****ing air .. this time i changed cables(ngk) spark plugs (Ngk cooper) , rotor, cap , and i cleaned throttle with carb cleaner before the new plugs , then i installed everything new .. haven't tried replacing the PCV valve or cleaning IACV tho

 

emissions on small cars are a complete joke and way to make money. I recently replaced all the emission related parts on one of my cars to make it pass. It wound up being a bad wire from the coolant temp sensor to the ecu.

 

You want your car as hot as possible to pass smog.

.

 

Copper plugs are slightly better performance wise than precious metal plugs (contrary to marketing BS).

The precious metal plugs are better at lasting longer. They are best used in applications where its a pain the %#@^$#&# a$$ to change the plugs (for instance when you have to take half the engine apart/remove the intake to chang the plugs). I used platinum in my Ford Escape because accessing the rear 3 plugs is a 3-4 hour job and requires replacing manifold and EGR gaskets.

In a car where changing the plugs is relatively easy I'd use good old NGK copper plugs gapped to spec to try and pass smog.

Always use antiseize compound on aluminium heads, hand thread and torque to spec with an appropriate torque wrench.

 

Did you double check the plugs to make sure they are the right part?

The gap should be .44 by the way.

Does your CEL work?, turn the key and see if goes on for a second and then off.

Your cat could be bad.

 

tripple checked the part number , honda manual said .40 -.44 and we left it on .40 , CEL light works fine , we also scanned it .. first time i failed smog i changed plugs , cables and everything same night , and took it to get it tested next day .... can that be the problem that maybe i should let the car adjust to the changes?

 

What about a simple thing like oil and filter change prior to the test?

Someone's advice here to have fully warmed up for the test is no bull.

 

it's NOT your plugs change the oxygen sensor . then if level's are still high your cat is proably bad . if you have a scaner or occilascope then you can monitor the oxygen sensor's front should switch between .2v and .8v rear should run fairly flat around .4 or .5v

 

second o2 is new altho the previous owner had after market header and put the front on the place where the secondary goes , but what i dont understand if the first time i tried was at 77 then changing plugs and oil it went up the roof

 

timing? I would gap your plugs out alittle more, replace front o2... Or get it scanned

 

Just because your problem was due to bad coolant temperature sensor, it doesn't mean those other things can't cause problems as well. It's just unfortunate that you, like many others, found yourself throwing parts at the car before eventually uncovering the actual problem.

 

Try to open the gap to .44, like I said could be the cat as well.

Try to retard your timing by a few degrees for the test.

Stupid as this sounds, many years ago I used a product guaranteed to pass, you poured it into the gas tank, before inspection on my sis's car which failed, and it did work. I am not sure if they still make it.

http://www.crcindustries.com/auto/co...x?PN=05063&S=N

http://www.amazon.com/CRC-05063-Guar.../dp/B000CIPUR8

 

He should redo his electrical grounds and get a multimeter and measure them. If the o2 sensor's ground is higher than 2 ohms, the o2 sensor won't get its signal to the ECU and therefore 'not work'. O2 sensors use the exhaust manifold as the ground and if the ground cable for the alternator or whatever is dirty/weak, then so will the ground for the o2 sensor.

 

I heard some acetone in the fuel tank (very similar to petroleum distillates, an active ingredient in many popular fuel system cleaners)- works to help clean up emissions.