Source for new IMRC module?

I’ve got a ‘98 Cobra with 50k miles.

A few months ago (so at 49,850 miles as I don’t drive the car much) I got a CEL and the code was P1516. I pulled the intake and IMRC plates, cleaned everything up real well and put it back together. I drove the car 7-10 times for fairly short trips (less than 30 minutes each time) and never had any issues or another CEL.

Last week I drove the car a good hour and a half, parked, came back out 30 minutes later and headed back home. About 10 minutes into my trip the CEL comes on. Another P1516 code.

Both cables still move the butterflies freely, and since I just cleaned the IMRC plates I can’t imagine the code is indicating they’re stuck or dirty again, so I’m thinking maybe the module is on the fritz. Another thing I thought was maybe after a really long drive and an extended period of heat, some connection in the module is separating or coming loose due to the heat, and then the module malfunctions and throws a code.

Thoughts? Are there any sources to buy replacement modules, or maybe ones that have been Re-furbished to like new condition?

98 svt said:

@mwolson

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Agree - reach out to Mark, as he can test and rebuild them.

OP, besides the CEL, how does the car perform through the 3250 RPM transition zone?
As you work through this issue, you might consider adding an oil catch can to your PCV system.

Tillerman77 said:

OP, besides the CEL, how does the car perform through the 3250 RPM transition zone?
As you work through this issue, you might consider adding an oil catch can to your PCV system.

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There is absolutely no change in performance after the CEL trips. Car behaves exactly the same throughout the entire RPM range before and after the CEL.

This makes it even more frustrating, because I’m just potentially fixing a stupid CEL and not a performance issue.

Interesting. It would be worth emailing Mark Olson about your symptoms, as he has a lot of knowledge on Mustang electrical issues. He is a semi-retired EE.

Consider deleting them. I did on mine last month and been extremely please with the outcome.

The work you'll have to do to place the system will be alot to just have to do again in a few months. That was my main reason for deleting

Sent from my 5032W using the svtperformance.com mobile app

Livin'svt said:

Consider deleting them. I did on mine last month and been extremely please with the outcome.

The work you'll have to do to place the system will be alot to just have to do again in a few months. That was my main reason for deleting

Sent from my 5032W using the svtperformance.com mobile app

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Valid point - that said, there are many owner's who are still running the IMRC system without recurring issues, even up to well over 100K in miles.

Only reason I deleted mine was that the passenger side cable was cut or snapped. That being said, I got a tune for it after, and I do feel a difference.

I've thought about deleting them, but am trying to avoid that if at all possible. The rest of the car is pretty much stock except for suspension and 4.10s, so I'm trying to keep it as close to that as possible. Of course if a replacement for the module isn't possible, that may be my only option to avoid a CEL.

Once they're deleted, I know it's recommended to get a tune which can also turn off the CEL. How does the tune affect the OBD2 scan during emissions testing? Is the fact that this IMRC system missing, and was throwing a code, totally wiped out and not at all visible to the emissions testing folks and their scan?

Depending where you are, most states allow 1-2 not ready codes last I checked. A car in MA only needs to be 15 years or older to just get a safety check.

OP - when I was searching for another IMRC control box a few years ago, I used eBay and the WTB section of this forum to find one. That said, I see Mark Olson has not been on this site since April 11th. If you are still wanting to check in with him, his website is here. His phone number is listed on the site.

Tillerman77 said:

OP - when I was searching for another IMRC control box a few years ago, I used eBay and the WTB section of this forum to find one. That said, I see Mark Olson has not been on this site since April 11th. If you are still wanting to check in with him, his website is here. His phone number is listed on the site.

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Awesome, thanks for the information. I've noticed he hasn't been on for awhile but I'll reach out to him this weekend and see what his thoughts are.

I considered going the eBay route as well...but like with most used parts, you just don't know what you're going to get. I was hoping to find a really reputable source for getting a re-manufactured one, and sounds like Mark Olson may be a good place to start. If for nothing else, just information.

boostfrk said:

Awesome, thanks for the information. I've noticed he hasn't been on for awhile but I'll reach out to him this weekend and see what his thoughts are.

I considered going the eBay route as well...but like with most used parts, you just don't know what you're going to get. I was hoping to find a really reputable source for getting a re-manufactured one, and sounds like Mark Olson may be a good place to start. If for nothing else, just information.

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You're welcome. I worked with him in 2017 to check over a control box that I had gotten. I recall that he can test, repair and I think he can deal with broken cables/cable ends too.