Check Engine Light

I have a 2000 Ford Contour SE with approximately 125,000 miles, with 2.5L engine. Since Feb '07 my check engine light has been on. I have replaced all plugs and wires, fuel pump 2 times and fuel filter 3 times. I have replaced 3 O2 sensors as well as 2 IMRCU's. Loss of power starts at around 1/2 tank of gas, bucks and stalls (acts like it is out of gas). RPM's stick around 3000 with foot off the pedal and takes a minute to idle down to around 750 rpm. Throttle plate has been cleaned. Is it an actuator, a vacuum leak? I have spent more than $2000 :banghead: on this car in 9 months and it is no longer worth that according to blue book. My car won't pass inspection this Feb with a check engine light on, will it? Any help would be greatly appreciated at this point. :runaround:

Thank you
Mamabear0917

So what was the code when you got the CEL pulled?

Last week when I replaced the O2 sensor the code said something about running too rich/lean bank 2 (that's all my mechanic will tell me, no "codes"), replaced the one on the drivers side near the converter. A couple of weeks ago when IMRC was replaced it was stuck wide open. It seems that once the IMRC is replaced (warrantied, thank god), then the sensors need replaced on bank 2, once they are replaced we are back to the IMRC code. Someone told me I had a vacuum leak but when I asked my mechanic he said he never heard of such a thing.:uhoh: I'm looking at all the codes and the info on rich/lean codes and "A lean fuel condition may exist if the engine is sucking in too much air and/or the fuel system is not delivering enough fuel. If bad enough, a lean fuel condition may cause lean misfire, a rough idle, hesitation or stumble when accelerating, and/or poor engine performance." This is exactly what I have been experiencing since Feb.

Well, it can only be a rich or a lean code. It cant be both, but If i had to guess its probably lean judging by your symptoms.

First of all, if your mechanic has never heard of an intake leak, its time to find another mechanic. Gaskets wear out. Unmetered air enters the engine. Nuff sad.

Secondly, if your car reads a rich or lean code, chances are your O2 sensor is working properly. People automatically seem to think that if their engine is running rich or lean that there O2 sensor must be reading incorrectly and must be broken.

Third, what it seems like to me is if your secondary valves are sticking open, that seems like a lower intake manifold issue, not a IMRC. Yes, the IMRC does open the secondaries, but generally when the IMRC malfunctions, the secondaries stay closed, not open. You might have a lot of carbon build up on the secondaries which is keeping them open. If your upper and lower intake manifold gaskets have never been replaced, its probably a good time to change them. Thats typically the gaskets where an intake leak occurs.

However, that being said, I would guess your problem is your fuel pump. Only the 2000s had a returnless fuel pump which is notorious for going out. Every other year is fine. If the hesitation gets worse as your fuel level decreases, thats pretty much a guarantee its your fuel pump. Check contour.org in the duratec maintenance forum on the howto to replace it.

Try replacing the Idle Air Control Valve (IAC) Your idle should not be that high. This can also cause a rich / lean mixture if not operating properly. Located on the backside of the engine on top intake drivers side. $50.00 part. Take your car to autozone and have them check the codes!! Why spend money getting them checked when autozone does this for free!!!! Get another mechanic also.

I have a 98 SVT and my check engine light has been on for a while. Ive taken it to AutoZone and they told me that it was my O2 sensor. Replaced that and the Check Engine light goes off until I restart my car, then is back on. I went back to AutoZone and they ran a diagnostic again and they said it was my O2 sensor. I am not sure what else to check. Any suggestions?