So currently I still have my 87 N/A and saw a 91 T2 for sale around my area. I’ve been digging around for a little bit researching s5 fc’s now that I have my eye on this 91 T2. I already know that mechanical wise the s4 N/A and T2 beats out the s5 N/A and T2. So basically what I’m going to ask is. Has there been a new solution to fixing the EOMP on the s5 from failing and frying the ECU while the EOMP is failing? So far all I know is either sourcing out a OEM s5 N/A or T2 ECU chipped tune by Rtek7. But with it being 2025 who’s to say those used ECU tuned by Rtek even works anymore. Next is Banzai’s PowerFC plug n play harness/Apexi FD ecu. With it also being 2025 I’ve been hearing that it’s pretty much old ancient technology at this point. Next would probably be another ECU something like Haltec. Seeing as the 91 T2 I’m looking at is stock I really don’t feel like spending $1500-2k for a Haltec or PowerFC just to bypass the limp mode because the EOMP failed. If I do get the car I planned to keep it mostly stock and is prioritizing maintenance/cooling mods. Hence why I see getting an $1500-2000 ECU kind of useless to me.Forgot to mention EOMP still works on the 91 T2 that I was looking at but just planning for the future and see if I can prevent it.

What’s done to the car atm. Forgot to mention went and looked at it. Also had some sort of big radiator. From what I could gather it seems to be like an oldschool Koyo radiator not to sure as it doesn’t have brand name on it.

Photo of unbrand name radiator


Different FC with a similar radiator and guy said in his mod list that it was a big koyo radiator. But just wondering if anybody here knows.

 

The radiator looks like the Koyo N-flow.
As to the ECU/ OMP. I don't think there is a solution that prevents the OMP from damaging the ECU when it fails sometimes. That said I wouldn't let that deter me from buying a S5 but I like the S5 better so I may be biased. What I would probably be more concerned about is the full Racing Beat exhaust and no mention of a fuel cut defender which is really just a Band-Aid of sorts. It disables the factory fuel cut above a certain boost level. Also is it the Rev TII that is a full 3" or the one that is 2.5". Either one will increase boost due to the increased flow but the 3" will raise it more. This alone would be a valid reason to consider a standalone ECU as the stock one may not be able to adjust enough to deliver the needed fuel. With the standalone it can be tuned for this increased boost. Though the PowerFC is considered old tech it does work well and a lot of people still run them. I might lean towards the Haltec just for newer tech at a similar price.

 

So found out it’s the 3” REV T2 exhaust. So I’ll probably ask the seller to check out the ecu next lol. Cause no FCD or aftermarket ecu is kinda crazy for running the 3” REV T2.

 

So the guy compression test if with a normal piston comp. tester and is getting 60-65 psi on both front and rear. But the crazy thing is when I went to look at it and test drove it. It started up fine cold with no little to no smoke. Let it warmed up and it held idle, then went on test drive (test drive and went to go looking at this car was before I made this post not knowing the stuff I knew now.) test drive went I would say good, it pulled hard with no hesitation. Only thing was it backfired at 3k rpm when coming off the gas pedal. Hot started with no problem as well. When hot started would kind of have to blip the throttle a little and then the idle will hold at a steady idle. Which I assume it just needs a TPS adjustment. I like to also mention that installing an aftermarket ecu like haltech or PFC is something I never done before. Basically wiring isn’t my strong suit. Ik there is a whole bunch of right ups for these. But not to many videos out there.