Dang CEL again... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Boxtaboy · 01-16-2010, 01:02 PM

Ok, a few months ago, while pulling into my office parking garage at a steep incline, my CEL came on. Bought a code reader, and it said the code was P1128. Only one bank. I cleared the code, and it didn't come back for over 500 miles. Thought it was just a fluke.

Then, last week, at the same incline at my work garage, it comes on again. I clear the light again, and then 60 miles later, it comes on again. Just cleared the light again. During all this time, I am not experiencing any strange engine idle or drivability issues. Power seems strong, and car runs great. No smoke at startup from tailpipe or anytime thereafter. Any ideas anyone? Car is at 61k miles and is an 01 Boxster.

gschotland · 01-16-2010, 02:58 PM

Have you replaced any of your O2 sensors? Maybe one's preparing to die on you. One of mine failed at 64k and I replaced the other 3 a few thousand miles after that when I read here that it's best change them all at once. The car was running fine, but it ran noticeably better after all the sensors were replaced.

Also check out this current thread:

http://986forum.com/forums/showthread.php?t=23320

Boxtaboy · 01-16-2010, 03:09 PM

Thx. Nope, I have not replaced the sensors yet. Come to think of it, have not changed the MAF or AOS either. Guess lots of things start to go at this age. Lol. Any way to tell for certain it's the O2 sensor?

mikefocke · 01-16-2010, 03:21 PM

"while pulling into my office parking garage at a steep incline" means that a shift of the engine is happening opening a crack in the air intake leading to the P1128.

I can't see the shift affecting the MAF or fuel pressure so, since the air intake leak is the second cause listed under that fault code, ....

Ever looked at or replaced your motor mounts?

Boxtaboy · 01-16-2010, 03:39 PM

Motor mount replaced a few thousand miles ago. I thought the incline had something to do with the fuel pump or clogged injectors, but today when the light came back on, I was on a level surface.

Lil bastard · 01-16-2010, 03:54 PM

MAF gone bad.

Cheers!

Boxtaboy · 01-16-2010, 04:07 PM

Guess I have some troubleshooting to do.

Thx all.

Paul · 01-16-2010, 07:14 PM

Has your 60K service been done yet? If not, clean the MAF while you're at it.

Boxtaboy · 01-17-2010, 03:29 AM

Yep. Did the 60k service already, including plugs, motor mount, and water pump too. Will prob just buy a new MAF since I hear cleaning is only temporary. Thx.

JAAY · 01-17-2010, 05:41 AM

MAF and 4 DIY O2 sensors from napa and you will be golden. Bring her here if you need help.

Boxtaboy · 01-17-2010, 06:38 AM

Hey thanks Jay. Will try the Maf first. If that no workie, I'll try the sensors.

docster · 01-17-2010, 10:58 AM

My CEL light has been coming on for over a year now. The OBD II shows P1128. I've gone over 2000 miles without it coming back on (a trip from OR to CA and back). I just cleaned the MAF and it came back on after less than 100 miles. The car seems to run fine and I just clear the code. I guess I'll try replacing the MAF with a new one, if I don't find any other solutions. I have a little over 30,000 miles on the car. No other problems. Only mod is snorkle removal.

The two Porsche dealers in the state are at least 100 miles from me and I have yet to find a local mechanic I trust. Other reliable non-dealer Porsche shops are just as far.

Looking forward to any solutions found to this problem.

2000 Boxster, Arctic Silver/Black