P1128 and P1130 - only after a few sessions of "spirited" driving

[steved0x]

I have posted about these codes before when I was in NC, and since coming down to FL I have barely gotten them. When I do, they usually turn off after a day or so. I also am getting two other codes, P1117 and P0139, for the oxygen sensor behind the bank 1 cat. They are always there and if I clear them, they immediately come back as pending. I have a new oxygen sensor and plan to replace that.

For the P1128 and P1130, I have done a lot of searching and I haven't found one that seems to match my circumstance. I only seem to get them if I have recently been up near redline. They will show up usually as I am stopping like at a red light or some low power situation.

Since they only seem to come up after getting near to redline (but not bouncing off the rev limiter, I don't think I have ever done that), does that give any clues?

I have seen some reports that seem to say that the MAF doesn't do much at WOT/Redline type situations, and others that say the MAF does nothing at idle and only is critical during high power/high throttle.

I have seen other threads that suggest vacuum leaks. Maybe the leaks only manifest at WOT?

However my codes are for idle (engine running very lean and the fuel adaptation has pegged its rich correction) but it only seems to occur after spirited driving. Odd.... maybe it is a big coincidence. I did not get this CEL after my one track day...

I've got some troubleshooting steps (thanks Paulv) but I was hoping the additional information (the CEL only comes on after high spirited driving and then goes off in a day or two) might give some clues and short-circuit some of the steps.

I do have a new MAF so maybe I just need to finally install it... Every time I am going to do so the CEL goes off and so I don't do it... I am taking some time off for Christmas so I will probably just do it.

If anybody has any non-MAF suggestions I would love to hear them and I will report back when I have replaced the MAF and done some "test" driving.

Thanks,

Steve

[steved0x]

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[silver-S]

I got these codes when my air-oil separator went bad. Simple test: if you can't get the oil filler cap off when the engine's running, that's your problem. The bad AOS puts a fierce vacuum in the filler tube. You may see a big burst of white smoke on starting, but I've also seen a Boxster trailing a faint stream of burning oil smoke that the owner was probably unaware of. Worth checking, in any case, since it's an easy test for a common problem.

[brian325is]

I had the same problem as silver-s. Kept cleaning my mass air flow and the code would come back.

Changed the AOS and the oil filler tube and the code is gone. The filler tube had a leak somewhere. You could see a build up of oil and dirt on the tube.

Must have caused a vacuum leak. BTW my car passed the oil cap vacuum test.

[sb01box]

i've had the same 1128-1130 code pop up on my drive home from work.
spirited freeway driving for about 7 miles
on to city street at about 40 mph for 1/2 miles
while coasting to a stop at a red light, the CEL lights up
always 1128-1130 combo.
clean maf and did the job for about 1 year.
started to get the same code after same drive.
replaced maf. no more CEL 1128 1130 for 2 years now

[Topless]

1117 and 1139 look like a failed O2 sensor or damaged wiring. Fix those first and see if the others come back.

If 1128 and 1130 return it means your car is running lean. Either a failing MAF or intake air leak most likely. Failed AOS will cause an intake air leak.

[steved0x]

Originally Posted by brian325is

I had the same problem as silver-s. Kept cleaning my mass air flow and the code would come back.

Changed the AOS and the oil filler tube and the code is gone. The filler tube had a leak somewhere. You could see a build up of oil and dirt on the tube.

Must have caused a vacuum leak. BTW my car passed the oil cap vacuum test.

My car passes the oil cap vacuum test, but I will check that tube as I did blow a smoke bomb at my last track day. I believe it was because I had accidentally overfilled the oil at my previous oil change (since resolved by dropping the oil filter)

I have had the oil filler tube and AOS replaced within the last 50,000 miles, but as I am realizing, just because it was replaced once in the past doesn't make it a lifetime fix

Steve

[steved0x]

Originally Posted by silver-S

I got these codes when my air-oil separator went bad. Simple test: if you can't get the oil filler cap off when the engine's running, that's your problem. The bad AOS puts a fierce vacuum in the filler tube. You may see a big burst of white smoke on starting, but I've also seen a Boxster trailing a faint stream of burning oil smoke that the owner was probably unaware of. Worth checking, in any case, since it's an easy test for a common problem.

I pass the vacuum oil cap test, but at my track day a few months ago I had someone report that they saw a faint stream of smoke behind my car.

Do cars pull more vacuum at WOT/High RPM/High power situations?

If so then maybe I am at preliminary stages of AOS failure?

Fun times this Christmas break

Steve

[steved0x]

I just dug out my service records, my AOS was replaced 11,000 miles and around 18 months ago. So I am going to try the MAF first since that has been longer.

I also have on the schedule to replace my spark plugs, and spark plug tubes and O-rings as they are weeping a little bit of oil, and so maybe this oil is somehow smoking.

MAF is easier to replace than AOS anyway

Steve

[opus69]

I have had these codes off and on since replacing the aos. It seems to go away in cold weather and when it warms up it comes back. Assuming a vacuum leak but haven't had time to track it down.