Loss of power, 3000 plus rpm issue

[sigtwenty]

My 01. Has a loss of power and poor mpg
Makes a loud whooshing noise at all times.


At idle, it's smooth. Perfect.
Power is weak all around. However if kept under 3000 rpms no check engine lights pop up.
At 3000 and above I'll get a misfire code on pass bank.
If I push it over 3000 it stains to get there, generally caps out at 3500. Then I'll get misfire codes on all 4 cylinder on that same side. It's always the same side.

Randomly I'll get a code for p1423 sec air issue and p0173 fuel trim but not as consistent.

When in heavy traffic and going back and forth with excessive stop and go sometimes a downshift will be rough. But only when going low speed stop and go and only after a while. It also does not do it all the time either. I know when I had bad cats but no cat codes on my old 96 it wouldn't let it shift into over drive gear.

When at idle, the car rpms do not fluxuate at all. 601. 605. 610. 602. It sits perfectly no ups and downs. Even visually on motor you could put a glass of water on it and it won't shake so to say. Put your hand on it and you barely feel anything abnormal.

I'm leaning towards a clogged cat. The p0420 p0430 codes have never popped up, not even pending or a ghost code.

Considering the codes are all on one bank I'm assuming that's the bank to look at. These 01s have 4 cats. I do live in an emissions required state.

Cars history. Vanos and guides been done. No noises. Car runs perfect otherwise.

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[Sobek]

I think you've nailed it - you've got 1 or more blocked cats. The rpm limitations, excessive noise, single bank misfires and fuel trim codes pretty much confirm that - probably one of the most complete and direct diagnostics of a blocked cat converter that I've seen actually. Sounds like you're on the right trail, I also imagine that secondary air code will stop once you resolve this issue too, I seem to recall a couple of years back we had a couple of bad cat posts that also had corresponding secondary air codes & fuel trim issues that resolved once the cats were replaced / deleted.

Good luck mate, always nice to see you around the boards

[sigtwenty]

I think you've nailed it - you've got 1 or more blocked cats. The rpm limitations, excessive noise, single bank misfires and fuel trim codes pretty much confirm that - probably one of the most complete and direct diagnostics of a blocked cat converter that I've seen actually. Sounds like you're on the right trail, I also imagine that secondary air code will stop once you resolve this issue too, I seem to recall a couple of years back we had a couple of bad cat posts that also had corresponding secondary air codes & fuel trim issues that resolved once the cats were replaced / deleted.

Good luck mate, always nice to see you around the boards

It's weird too as there wasn't any sec code before and then randomly came up and that plastic hose isn't cracked or anything.


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[Sobek]

I too wondered why a cat converter issue would throw a secondary air code, but my best guess is possibly back blow of exhaust gases into the secondary air system / valve through the aluminium pipe that slots into both banks' just before the exhaust is triggering the emissions system somehow... maybe it forces the valve open or something?

[shenofjo]

looks like someone needs to go to the pet store and get a new cat

[sigtwenty]

Update: a local enthusiast came thru to me with a full exhaust. we installed it today, for free....and my car works as it should now. we didnt cut the old one yet to see how bad it was, but ill probably do that soon for some giggles. I can redline the car now! haha.

[sigtwenty]

Additionally, for purposes of diagnosis.

CODES:

P0173
P0139
P0300
P0301
P0302
P0303
P0304
P1423

These codes were present, however generally random. the misfire codes were all the same side always. 2 days of driving, no codes, not even a pending one.

[Jamos]

Sig! Been wondering where you've been hiding.

Everyone's coming out of the woodwork now that the seasons changing