Now this is the 50,000,000 dollar question. Exactly how do I test them? Cause the **** port design on the OBDI system doesn't throw a code and if it does, whoopty doo...it doesn't say squat.

 

Any advanced scanner can plug in and monitor everything. Based on your description, the most likely suspects are a stuck open EGR or the MAF.

 

I've got a digital scanner that works on my fox. Told me what I needed to know.

Had a highly recommended mechanic try to figure out why my CEL went on and off. He had no answer.

Bought the scanner(~$200), hooked it up. It said o2 sensor. Replaced it and voila no more CEL.

Technology is wonderful.

 

Well my check engine light doesn't stay on, it goes on, then off, then back on, then back off. When it comes on its for 2 minutes at a time if that long.

My car has no cats so O2s are useless on it.

I thought about the EGR too, but I believe that was changed out in 07.

 

O2's aren't useless at all. They are a deciding factor in how much fuel you're using. Only OBD-II systems monitor the cats.

Also, just because a part is new, or fairly recently replaced, doesn't mean it's not bad. I've had brand new parts fail right out of the box.

I suggest you find a tech that has a really nice scanner and knows how to use it, so he can monitor the PID's and datalog the voltages and find the problem.

 

Well it's not that big of a deal, or at least I don't think. I just need this car to work till April 3-5th when I'll get my 08 back. On Saturday and Sunday I'm driving the V6 since my fiance' doesn't work.

 

If it were some kind of simple/cheap fix I'd have no problem doing it. But if it becomes too involved screw that cause I'm probably gonna sell the car in the near future.

 

That was what my CEL light was doing.

It WAS o2 sensors...

If you are hell bent on keeping your exhaust. Weld in bungs and install o2 sensors. Or get a new computer(super expensive). Find someone that has a scanner(CHEAP) and run the codes. The fox computer like many others uses the o2 sensor readings to control the engine.

 

I put a new ECU in the car.

Yeah I had figured the O2s may be at fault for at least the check engine light.

 

ECU will not delete your EGR/o2 systems unless you program it to. What ECU are u using? From my LITTLE research... only the AEM has that capability. AEM computers are 2 grand...