At my wits end.
04-26-2011, 08:14 AM
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At my wits end.
ok so I put an after market exhaust on my 90 accord lx stock. Manifold to tail pipe. I added headers. OEM Cat new. Didnt change the O2 sensor but I did have to modify the wiring since it further down the line. Didnt have any issues like this before replacing the exhaust. The O2 sensor is no longer on the exhaust manifold its further down the line. Car started running like crap. Seemed it wasnt getting enough air. Bought a cold air intake seemed to be ok for awhile. Now that its getting warmer out its acting up again. When the car is cold I will loose power back firing through TB. Sometimes when I push down completely on the gas and open the TB it will kick in and get "past the bogging down". My MPG is think it off as well. Only getting 25MPG (mostly HW). When I unplug the O2 sensor the issue goes away...kinda. Still feels like its not getting enough air. When I really get on it it seems like its wanting more air. Could it possibly be an O2 sensor ? PCV Valve ? I have recently also replace FITV (junk yard) IACV (junk yard) / Both cleaned up before installing (https://honda-tech.com/forums/honda-accord-1990-2002-2/cleaning-iacv-fitv-tb-1844067/). I replaced them because of a racing idle which was fixed once I replaced them. Throttle cable (new). Cleaned EGR valve and ports. Completely lost here. Getting tired of going around in circles chasing this thing. I think Im at a point where I might be making things worse. I really love this car and want to get it to a point that it runs and Im not exactly tinkering with it every weekend. Thanks in advance guys.
04-26-2011, 08:23 AM
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Re: At my wits end.
ok so I put an after market exhaust on my 90 accord lx stock. Manifold to tail pipe. I added headers. OEM Cat new. Didnt change the O2 sensor but I did have to modify the wiring since it further down the line. Didnt have any issues like this before replacing the exhaust. The O2 sensor is no longer on the exhaust manifold its further down the line. Car started running like crap. Seemed it wasnt getting enough air. Bought a cold air intake seemed to be ok for awhile. Now that its getting warmer out its acting up again. When the car is cold I will loose power back firing through TB. Sometimes when I push down completely on the gas and open the TB it will kick in and get "past the bogging down". My MPG is think it off as well. Only getting 25MPG (mostly HW). When I unplug the O2 sensor the issue goes away...kinda. Still feels like its not getting enough air. When I really get on it it seems like its wanting more air. Could it possibly be an O2 sensor ? PCV Valve ? I have recently also replace FITV (junk yard) IACV (junk yard) / Both cleaned up before installing (https://honda-tech.com/forums/showthread.php?t=1844067). I replaced them because of a racing idle which was fixed once I replaced them. Throttle cable (new). Cleaned EGR valve and ports. Completely lost here. Getting tired of going around in circles chasing this thing. I think Im at a point where I might be making things worse. I really love this car and want to get it to a point that it runs and Im not exactly tinkering with it every weekend. Thanks in advance guys.
What you have to realize is that they place the 02 sensor closer to the engine for a reason, so that it heats up and starts working. It needs to be hot. If your sensor is too far then it might not ever get to operating temperature.
04-26-2011, 08:26 AM
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Re: At my wits end.
I would definitely suspect the O2 sensor first.
What you have to realize is that they place the 02 sensor closer to the engine for a reason, so that it heats up and starts working. It needs to be hot. If your sensor is too far then it might not ever get to operating temperature.
What you have to realize is that they place the 02 sensor closer to the engine for a reason, so that it heats up and starts working. It needs to be hot. If your sensor is too far then it might not ever get to operating temperature.
04-26-2011, 08:52 AM
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Re: At my wits end.
Give the new O2 Sensor a shot and let us know!
04-26-2011, 09:12 AM
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04-26-2011, 09:18 AM
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Re: At my wits end.
Sounds like you purchased the incorrect header for your vehicle and then did a whole bunch of unnecessary crap trying to fix the first problem (that you didn't and still haven't fixed.)
Put the stock header back on and I wager all your issues go away.
Put the stock header back on and I wager all your issues go away.
04-26-2011, 09:39 AM
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Re: At my wits end.
Well I dont think Ive done any unnecessary crap. IACV FITV were replaced and cleaned cause I was having an issue with the surging idle. Cleaned the EGR valve because it pretty much needed it. A lot of carbon build up. throttle cable was replaced because it was frayed and just in bad shape. But you are 100% correct. I did purchase the incorrect header. Fail on part. Measure twice cut once.
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04-26-2011, 09:40 AM
#8
Re: At my wits end.
I would definitely suspect the O2 sensor first.
What you have to realize is that they place the 02 sensor closer to the engine for a reason, so that it heats up and starts working. It needs to be hot. If your sensor is too far then it might not ever get to operating temperature.
What you have to realize is that they place the 02 sensor closer to the engine for a reason, so that it heats up and starts working. It needs to be hot. If your sensor is too far then it might not ever get to operating temperature.
If however, your sensor is old and sluggish, or is biased towards lean (which would cause the engine to inject too much fuel) it will do what you are saying.
You say the sensor is further down the line. Where exactly is it? Is it in the collector of the manifold in front of the cat or is it behind the cat?
04-26-2011, 09:54 AM
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Re: At my wits end.
No dude you're wrong. These cars use heated O2 sensors. Gets to operating temp within minutes of startup regardless of position.
If however, your sensor is old and sluggish, or is biased towards lean (which would cause the engine to inject too much fuel) it will do what you are saying.
You say the sensor is further down the line. Where exactly is it? Is it in the collector of the manifold in front of the cat or is it behind the cat?
If however, your sensor is old and sluggish, or is biased towards lean (which would cause the engine to inject too much fuel) it will do what you are saying.
You say the sensor is further down the line. Where exactly is it? Is it in the collector of the manifold in front of the cat or is it behind the cat?
Last edited by stang7043; 04-26-2011 at 10:09 AM.
04-26-2011, 10:25 AM
#13
Re: At my wits end.
Well, you unplugged the O2 sensor and the symptom went away. This likely caused a DTC and put the vehicle into open loop. I suspect sensor inputs causing the problem. If you graph the O2 sensor data you can tell if the sensor is giving bad input. You need a graphing meter. Regular volt meters either analog or digital aren't fast enough and are hard to read when looking for O2 sensor problems. Though, you can use one if you suspect a stuck O2 sensor.
04-26-2011, 10:34 AM
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Re: At my wits end.
Well, you unplugged the O2 sensor and the symptom went away. This likely caused a DTC and put the vehicle into open loop. I suspect sensor inputs causing the problem. If you graph the O2 sensor data you can tell if the sensor is giving bad input. You need a graphing meter. Regular volt meters either analog or digital aren't fast enough and are hard to read when looking for O2 sensor problems. Though, you can use one if you suspect a stuck O2 sensor.
04-26-2011, 12:24 PM
#15
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Re: At my wits end.
Well, you unplugged the O2 sensor and the symptom went away. This likely caused a DTC and put the vehicle into open loop. I suspect sensor inputs causing the problem. If you graph the O2 sensor data you can tell if the sensor is giving bad input. You need a graphing meter. Regular volt meters either analog or digital aren't fast enough and are hard to read when looking for O2 sensor problems. Though, you can use one if you suspect a stuck O2 sensor.
04-26-2011, 01:23 PM
#16
Re: At my wits end.
If the sensor is biased you can use a DMM. Don't remember if I said that, or not.
04-26-2011, 02:00 PM
#17
Re: At my wits end.
Well I dont think Ive done any unnecessary crap. IACV FITV were replaced and cleaned cause I was having an issue with the surging idle. Cleaned the EGR valve because it pretty much needed it. A lot of carbon build up. throttle cable was replaced because it was frayed and just in bad shape. But you are 100% correct. I did purchase the incorrect header. Fail on part. Measure twice cut once.
Yeah, the header thing I figured you probably had - my guess, along with yours, at this point is the O2 sensor being the culprit. However another thing to try which may help is the Idle Air Adjustment **** that is on top of the throttle body. It is a small brass screw that can help fine tune your idle - you may want to see if it is all the way shut or close to it. I would suggest opening it up a bit and see if it helps.
05-01-2011, 06:32 AM
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Re: At my wits end.
ok so I changed the O2 sensor yesterday with an after market Bosch O2 sensor. So far so good. Drove it a couple times at 30 mins clips. Tried to replicate what I was doing when the car acted up and so far the seems to be running ok. Ill have to give it a week to see how my MPG is. Before I changed it with it plugged in I was getting about 25 mpg highway/city driving. Ive had it unplugged all week and can see a noticeable loss in MPG. Heres to keeping my fingers crossed.
05-01-2011, 07:01 PM
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05-02-2011, 12:31 PM
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05-02-2011, 12:42 PM
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Re: At my wits end.
Ive read a few post / threads about this. And some people say not to some people say its ok. Since I had to extended the wiring I used it on the plug side but not on the o2 sensor side. From the threads Ive read people say the heat from the soldering iron can damage the o2 sensor or the soldering and wire metals are different and contract and expand at different rates. So that could break the solder joint. But I would like to know why also.
05-02-2011, 01:06 PM
#24
Re: At my wits end.
Ive read a few post / threads about this. And some people say not to some people say its ok. Since I had to extended the wiring I used it on the plug side but not on the o2 sensor side. From the threads Ive read people say the heat from the soldering iron can damage the o2 sensor or the soldering and wire metals are different and contract and expand at different rates. So that could break the solder joint. But I would like to know why also.
I had to do the wiring on my H22 Accord and soldered stuff without any problems.
