QuestionHello, Can a leaking fuel injector cause the HC level in the exhaust to increase? The first time it was tested it almost passed. Then the Fuel pump died and I replaced it and a few other things (both O2 sensors,Fuel and air Filters,cleaned EGR valve) had it re-tested and the HC level DOUBLED! And it failed again. I don't have the Emission gas levels with me but I can get that for you if you need it.
Also when the car is driven after about 10 min the Service Engine light comes on. But when I shut the car of, Install the Code Reader and turn the key to run the Service Engine light comes on and stays on. It doesn't blink a code. If you restart the engine the light is off for about 10min then comes on. What's up? Shouldn't the ECM store the Code?
Is the ECM Bad? Is there any way to check it?
Any help would be Great!
Thanks,Randy
AnswerHi Randy,
I found this question in the 'pool'. That is where questions go when the orginal person asked cannot answer it. I am letting you know in case it was there a while. Sorry about the delay in getting an answer.
First question = YES! a leaky injector will cause high HC.
All of the above stuff you replaced can cause HC. Changing them is good PM anyway. Part of a good tune up. But since it didnt work, you need to suspect other things. Injector is good place to start. Look for the wet plug. It will be wet if you have a leaky injector. Also can be a bad plug, or wire. I would change the plugs and wires. If you find a fouled one or wet one, that is the injector. Some scanners can actually disable injectors, one-by-one. This is good to see if disabling one changed the HC>
If you have HC, your O2 wont cycle. It will attempt to lean the fuel and stay high.
Your ECM is probably good. The 10 minute light is due to the computer deciding to let you know it sees a key on engine running condition it doesnt like. This is calculation of O2 readings. AFter 10 minutes, it decides it cannot adjust the rich fuel condition out. so it trips the light. ONce the motor is off, the code goes away. 1996 is the year of OBD-II and 'smart cars'. Prior is a crap shoot. Newer may store the code even if it is not a hard code. A soft code on older car like yours will erase when motor is off. Remember that the first 3 minutes is open loop. The computer has no control at this point. The remaining 7 minutes is closed loop and the calculation process.
Hope this helps. Mainly, check your plugs. You have a bad plug somewhere that will tell you what you need to know.
C J S
