A Few Questions...

cleancutlawnservice · July 27, 2009

My girlfriend has 99 Camaro, 3.8L V6, automatic, I know its not a truck but thought you guys might be able to help me?

We were cruising on the highway and suddenly got a pretty bad vibration and the check engine light came on and began flashing.

Limped to the auto parts store and got the codes pulled.

PO300 random misfire

P1404 emission controls

I bought some lucas injector cleaner and drove it around today. It runs really rough at idle and smooths out after acceleration. There is also a big loss of power too.

I replaced the plugs and wires less than a year a go and didn't see any visible damage to the any of the wires. Is there any way to pinpoint which cylinder is misfiring?

I've done a little research tonight and read about the EGR being clogged as a possible cause, thoughts/opinions?

I think the P1404 code is accuring because their is unburned fuel dumping on the o2 sensor, or at least thats what I am hoping. Would a bad o2 sensor cause the misfire?

I'm really limited on funds right now and am trying to be as smart and frugal as I can be dealing with this problem. Your advice and time are greatly appreciated. Thank you in advance.

jf781 · July 27, 2009

For starters I would pull the plugs and see if you can find one that looks dark/dirtier then the rest. That might help narrow down the cylinder that is having the misfire error. From there you could try changing wires/plugs to see if it follows the plug/wire or if it in the coil or injector.

Thats at least where I would start and then go from there.

bill190 · July 27, 2009

P1404 means the EGR - Exhaust Gas Recirculation valve is STUCK OPEN.

This valve sends exhaust gas into the air intake of the engine for "reburning" and this cuts down on emissions.

But there are only certain times when this can be done and the engine can still operate normally. Therefore this valve needs to be able to close at other times.

It is not closing. Try cleaning the EGR valve.

Then PO300 means sometimes you are not getting an "explosion" in various cylinders. You mix air, fuel, compress it with the piston, then spark and BOOM!

But if you are mixing exhaust gas instead of "air" with fuel, at certain times you may not get the "BOOM"!

So try cleaning the EGR valve and maybe things will work better.

So far as where this valve is located, this should be in a basic automobile repair book which might be available at your library. Or these are not too expensive at an auto parts store. Find one for your specific year/model vehicle.

How to clean EGR valve...

http://www.google.com/search?hl=en&q=c...;oq=&aqi=g7

If that does not solve the random misfire 300 code problem, here are more things to check...

http://www.random-misfire.com

cleancutlawnservice · July 27, 2009

Thank you very much for the advice. Definitely sounds like the EGR is stuck open, gonna start with that. Those are some great websites, both bookmarked, thank you!

I'm trying to avoid doing the plugs and wires again, because I have to pull the exhaust headers off to get to them, ugh. Will keep you guys updated.

cleancutlawnservice · August 9, 2009

I took off the EGR valve and it was not stuck open. I cleaned it and reinstalled it.

I pulled one wire off of the coil pack at a time and then started the car. I determined it was cylinders 1 and 4, both on the same coil pack. I replaced the coil pack and it didn't fix the problem. I then replaced the ignition control module and problem solved!

Thanks for the help guys.

cleancutlawnservice · August 12, 2009

Ugh, another problem. Do they ever end?

My girlfriend was driving today and the car stalled out twice while idiling at stoplights. It also feels like it slips when shifting from 1st to 2nd, but no other gears.

The check engine light is NOT on and the computer is not giving any problem codes.

I took it to a local shop that I have a good relationship with and they diagnosed it as a weak alternator because right before it would stall, the voltage would drop to below 12.

We couldn't diagnose what was pulling current that caused the voltage to drop which caused the car to stall.

Was wondering whether this was logical and whether you had any other ideas or suggestions. Thanks again.