Doug I think the problem might be your CV. When you say the car pulling time do you hear knocking or just the car not responding like it used to? If you hear knocking then it defenately is another issue, but if it,s only loss of power it could be your CV. Good luck

Thanks for the help. Turns out I was looking for a mechanical issue by insisting it was electrical...


I pulled the intake, the J boot and everything else I could off of the top of the motor. Everything looked OK there, so I changed wastegates underneath. No change. I pulled the midpipe off to check on the health of the turbine wheel and found my cat had broken to pieces. They turned sideways, blocked flow, and boom no power. I replaced everything from the elbow after the turbo with a new 3" system and the car ran extremely well. I say "ran" because about two weeks later the clutch disc failed...

It's way apart right now for coated rod bearings, a new SPEC clutch, a rebuilt head, a Vitesse MAF, 27/8 and more.

Now, why would the computer pull the boost back due to a clogged cat? By that I mean, how did it know something was wrong?

like you said, since the computer never showed limp mode via blink codes, it seems the boost pull was mechanical, caused by the clogged cat itself.

clogged exhaust = less flow = less boost = appearance of limp mode

the computer likely had nothing to do with it.

But it did...

I could watch it drop from reading 1.4-1.5 to 1.2, then cycle the key, and repeat it. There was a definite event when the needle moved towards the left, and it was repeatable. It happened every time, and not just once.

It's done and over with now, but I don't get what caused it.

If the cat was clogged or partially clogged, then you were probably overboosting for a moment, then the KLR kicked in and put you in limp mode.

Enough bypass to get the turbo spooled up, but once it got to a certain level maybe backpressure caused an overboost condition.

Good to hear that you fixed it, anyway.