P1128 & P1130 Fault codes advice
 

I got my durametric working on my 99 boxster. I got a P1128 & P1130 code which tells me oxygen sensing range 2 cylinder (1-3) and oxygen sensing range 2 cylinder (4-6). should I replace oxygens sensors? car has 77k on it. is replacing oxygen sensors difficult to do for a diy? Can anyone give me advice on how to resolve these issues?

I am no expert, but I saw those codes twice. Neither time was a bad O2 sensor.
The first time, the car wouldn't idle well and eventually would not start. A local indy shop told me to test the fuel pump relay,,, they were right and it was a cheap and easy fix. Doesn't sound like your problem though. The second time it was an early warning that the AOS was going out. Best test for that is to try to remove your oil filler cap while idling,,, too much vacuum/hard to remove may indicate bad AOS, along with increasing smoke at start up. Hope that is somewhat helpful.

As a first step, clear the codes. Then let the car go through several drive cycles - several starts and restarts plus a mix of street and highway like driving - until its ready to monitor the O2 system again. If the codes don't come back, then they were a false alarm. If they do come back, then further investigation needed.

Replacing the O2 sensors is not the first way to go. IIRC your Durametric might be able to test their voltages to see if they are working in range.

try cleaning the MAF sensor.
I've had the same codes come up.
MAF and throttle body cleaning did the job for2 years.
second time cleaning the MAF lasted a year.
replaced the MAF and approaching 1-1/2 years without these codes.
have 130K miles on my daily drive '01 2.7

P1128 & P1130 generally means your O2 sensors are working perfectly so don't change em. Search is your friend here to gain a better understanding of the problem:

http://986forum.com/forums/performance-technical-chat/16186-advice-cel-coded-p1128-p1130-2.html

P1128, 1130, etc explained
 

Here's some more info I put together based on info from my library's Mitchell system for 2000-2002 Boxsters (that have DME 7.2).

Regards,
paul...

Same thing happens to me a few months ago. I cleaned the MAF and cleared the error codes. Another 50 miles same codes again. Found out it was my AOS failing. I replaced it, cleaned the throttle body and MAF again. Throttle body was really gunked up. Problem solved and car runs better than ever!

P1128 & P1130 Fault codes advice
 

I've had the same error codes come up on my '98. cleaning the MAF is what did the trick.
Buy some MAF cleaner spray, and search Pelican Parts on how to pull it out and what tools you need. The spray and torx driver will set you back $10 and about 30-45 min of your time. It's an easy fix and easy to get to. While you're in there you can check your air filter and pull out any debris from the air box (I found 2 cigarette butts!).

The 02 sensor should take about one hour to change, unless it is rusted in place. One Boxsters I remove the bumper, wheel and shroud for ease of replacement. I think its a 7/8 o2 wrench. You want to fix this because your cats can clog if you don't have the right fuel mix.

http://986forum.com/forums/uploads01...1362524295.jpg
This is a healthy 02 reading

AOS thread


Oxygen sensors usually are not the problem, they are making you aware (warning) that you have a problem somewhere else.
The oil cap removal method is a very good test for AOS failure. If you experience dramatic RPM fluctuations when removing the oil cap, AOS failure is the problem, not the cap o ring.

new codes
 

this is an old thread but I'll see if anyone is still watching it.

I was getting codes 1126 and 1133. replaced the AOS, oil filler pipe and tube. still ran like crap. replaced the MAF, immediately started running better. cleared the codes thought everything was great.
after about 100 miles CEL came on again. this time with codes 1128 and 1130.
I haven't had time to check the usual suspects yet, but I think I can eliminate the MAF. the old one was obviously bad. not only was there a noticeable difference in how the engine ran, acceleration etc... but my LTFT readings went from 35.1 down to 0 +/- 5.
I know it is possible that the new AOS is also bad. but that would not be my first suspect. I had some difficulty getting the bellow on, so it is possible I torn it. that will be the first thing I check. then I guess a smoke test to check for leaks. I know that fuel delivery can also cause these codes, but I am not seeing any performance issues and acceleration is fine. no hesitation or stumbling.

Anyone else ever seen these codes come up after replacing AOS, MAF?