P1128 Code
 

Howdy folks.

I have been getting a recurring P1128 CEL code of late. I had it happen a while ago then it went away but now I am getting it every time I drive the car. No other codes such as P1130 have appeared. I have been just clearing them with my Autel.

I tried cleaning the MAF to no avail. Am I looking at a replacement MAF or vacuum leak or O2 sensor?

Any suggestions would be appreciated.

Dave
2001S

I had a vacuum leak when I had 1128 and 1130.

I went thru the P1128 & P1130 issue last year.

http://986forum.com/forums/boxster-general-discussions/72288-p1128-p1130-running-fine-turned-into-barely-running-engine.html

A new MAF solved my problems. It seems like for many people on the forum a new MAF solves their problems. It is an easy to change part, but not the cheapest. With your code only being on one cylinder bank it may or may not be the culprit.

If your Autel can read real time fuel trims you often see if you have vacuum leak without having to smoke test the engine. Search online for how to interpret long term and short term fuel trims.

Can your Autel read O2 sensor voltage? Another thing to check before changing parts.

I learned the hard way that having real time data helps so much to make an informed decision.

Rex I was thinking vacuum leak but would I throw both codes or is it reasonable that a vacuum leak would only throw 1128 and not 1130?

I am not sure. It was a couple of years ago and I don't remember details. I was running out of time for CA reg/smog and just let the indy sort it out. I think they hooked it up to a smoke machine and just plugged whatever it was back in. They charged me for an hour and nothing for parts.