Check Engine

[pryornfld]

Hello All,

Just a quick question: My Check Engine Light came on about a week ago and my mechanic said that there was a misfire on CYL 2 and it was running lean. He said that it could be the plugs or fuel filter or both. Any ideas or recommendations?

Thanks

[DRW1000]

What year, what engine and are there any other codes or drivability issues?

[cosmo1]

May not be relavent, but I got a CEL on my 99 Windstar. Had it scanned by Autozone for free. It came out to P0172 - too rich mixture. They recommended I change the O2 sensors. The sold me the factory sensors and lent me the removal tools ($15 deposit).

Changed both in 30 mins - took longer to jack up the car.

Restarted the car and the CEL was gone - I disconnected the battery for the entire job to clear all the codes.

Biggest O2 sensor tip - use the right tools - makes all the difference.

Cosmo..

[pryornfld]

The van is a 1996 GL(3.8L), and it has 165,000KM on it.It had the O2 sensor replaced 2 years ago(with factory FORD parts) so I'm assuming that this is not the issue. I'm not sure of what the codes where, but I do know for a fact that it definately included a misfire. The check engine light flashed several times during start then went to solid. It stated in the manual that if this happens then it is a misfire.

Here is the sequence of events as it happened:
Started the van, check engine light came on solid and stayed on.
Restarted the van again same day, check engine light flashed several times then came on solid.Notice during that start, engine was a little rough until light came on solid.
No other issues with regards to the performance of the van.

Do you think it could be the fuel filter causing the misfire and the lean code ? My idea is if the fuel is not reaching the injectors properly, then it could cause the misfire. As to the lean code, not too sure if this could also be the cause.

[DRW1000]

Well there are a lot of possibilities that could account for a misfire such as dirty injectors, low fuel pressure, insufficient ignition (plugs, cables...), clogged EGR ports.....

As for the lean condition this exisits when air has entered the intake system after the MAF sensor and thus the PCM (compturer) does not "know" about the extra air but it detects the lean condition at the O2 sensors.

You may have a slight vacuum leak somewhere. You may also have EGR port clogging or you may have a bad plug and/or cable. Your MAF sensor may be dirty or faulty. Of course these are guesses from a thousand miles away.

Since you have 165000 and assuming you are on your original plugs and cables that may not be a bad place to start as they are past their "best before" dates. A fuel filter replacement is also a regular maintenance item that could contribute.

I think your mechanic is starting at the right place.

[pryornfld]

How long of a process would it be to check out the MAF sensor and to clean the EGR valve?

[DRW1000]

Well it depends on the skills of the person doing the work. The MAF should not take more than 1/2 hour to an hour max

The EGR ports are a bit more complex as they are in the intake manifold. I am not that familiar with 1996 so someone else may have a better idea.

[DRW1000]

I did not mean for my post to sound sarcastic in any way. Many like to do the work themselves. It always takes me a lot longer to do any job because I take my time and I always drop some sort of tool or fastener.

[pryornfld]

Originally Posted by DRW1000

I did not mean for my post to sound sarcastic in any way. Many like to do the work themselves. It always takes me a lot longer to do any job because I take my time and I always drop some sort of tool or fastener.

No offence taken. I have very little hands on knowledge with regards to automotive work, but I do know the basics. I'm glad to get any help like from yourself that can save me money and frustration from having to take it to the garage. Anything that I can fix, I'll give it a try at least once.