Contour Enthusiasts Group Archives Forums General Troubleshooting IMRC, Cats, and PCM reflash

Alrighty, I've got some questions concerning my girlfriend's 97 Contour SE with 60k miles.

First, some background. The car seemed to have lost some power over the last month or so, and a couple times I thought I had noticed a sulphur smell after stopping the car. Sure enough, the CEL comes on, and the code is for the Cats. So, I figure that they're still under the 80k/8year warranty, and we take it to the dealer(Park Cities Ford in Dallas). The dealer says that the Cats are indeed bad, but a bad IMRC caused the Cats to fail. Now, they will replace the Cats under warranty, but not until the IMRC has been replaced. They also want to reflash the PCM for $90.

Here's the questions: Could the bad IMRC have affected the Cats? How hard is it to replace the IMRC myself? Does the PCM need to be reflashed, or just reset?

Thanks for any help.
Ben

How could the secondaries not opening or staying closed make the mixture rich enough to kill the cats?

Sounds more like an oxygen sensor issue to me, but I could be wrong.

Unless there's a bug in the PCM program that led to this, make the reflash necessary...

-Lance

I'm not sure how the secondary runners could affect the cats one way or another. I figure if it's broken, I'll try and replace the IMRC myself. Then I'll reset the PCM and take it back to the dealer to have the cats replaced. If there are any updates, I may even have them reflash the PCM.

Anyone who's changed the IMRC, how difficult is it? I've got a fair amount of mechanical knowledge, plenty of tools, and the will to give it a shot. Let me know if I'm crazy. . . :rolleyes:

Thanks,
Ben
1992 Sentra SE-R
GF's 1997 Contour SE V6

before you replace the IMRC, check the IMRC actuator. its the little silver box mounted on the front of the engine with a black cable housing that runs under your throtle body. it opens and closes the IMRC and can if it's not working you will get an IMRC code. My cable snaped a few months ago, causing a huge loss in power. if that's what is broken it's a very easy install. much easier than taking off the upper and lower intakes to get at the IMRC itself.

IMRC stands for Intake Manifold Runner Controller, which IS the metal box under the plastic fascia on the engine.

And a bad IMRC could cause the engine to run rich, because the PCM no doubt changes the fuel mixture automatically when it tries to fire the secondaries, and then when they don't actuate, it adjusts back to the proper mixture. After thousands of iterations of this, the cat probably could get clogged.

About the PCM reflash.

If the factory has a revised program for your car, it is probably to your advantage to have it done. Unfortunately, they don't tell us what the revisions are. It may or may not have been related to what you have experienced. I have never heard anyone complain about the results of reflashing the PCM. It could prevent some other problem in the future. Think of it a little bit like the dual mass damper. If the factory spent the money on engineering, there is most certainly some benefit in doing it.

By the way, they could have denied coverage completely since the part that caused the failure is not a covered item. Everthing hinges on the "causal" part.

Thanks everyone. I ordered the IMRC this morning from FordPartsOnline.com for ~$100 including shipping. I'm gonna install it early next week and try to get the cats replaced later in the week.

Big Jim, I agree with what you said about the 'causal' part, but why didn't I get a CEL for the IMRC? Especially if it can negatively affect the emissions control system. . . Also, even if they had denied coverage, I would've swapped out the IMRC and taken the car to another dealership to have the cats replaced.

It's too bad because I love the car, but this is the second relatively major problem we've had since buyng the car in February and it only has 60k miles on it. The first problem was the piss-poor engineered water pump that failed the night we bought the car!!

Thanks again,
Ben

I guess the main thing I was trying to say about the dealership being willing to help you with the cats even though it may have been a gray area is that they were really being helpful. When all is said and done, make sure that you thank them. They did not have to be so helpful.