P1126, P1133?

[Pez]

Greetings,

I have searched the site countless times for something close to the codes my boxster is throwing, but not having much luck.

Last week I got a P1126 code, I retightened everything on the intake side and looked for vacuum leaks, and I could not find any. I cleared the CEL and a couple of days later when I started the car up it had a rough idle when it was cold, seeing it was close to the 30k check up I just took it to the dealer. I asked them to look into the code and the only thing they could find was that the “fuel adaptive was skewed rich” but was not enough to do anything. So about 3 days later the CEL comes back on with a P1126 and a P1133 (the P1133 throws the wrench in :huh: )?

The car is a 2000 Boxster 2.7

I installed an Evo quickflow intake about 8k ago but have not had any CEL’s turned on from it. This is my suspect, but one would think this the intake would lean out the car more then make it run rich.

Any ideas?

Thanks,

Chris

[insite]

one would think this the intake would lean out the car more then make it run rich.

<{POST_SNAPBACK}>

you are running lean. 'enrichment limit' or 'rich threshold' mean that the car senses a lean condition even though the DME is already at max rich. this means that:

1) your MAF is not sensing enough incoming air and needs to be replaced

2) your MAF is correct and you are sucking in extra air from somewhere

else.

check your oil fill hose, your throttle / intake manifold clamps and your oil separator bellows, as these are common culprits for vacuum leak. maybe use some propane around the motor while it's running to see if there's a leak (RPM's will jump when propane is inhaled). alternatively, you can spray brake cleaner around to see if the RPM's jump, but i'd stick w/ propane.

if none of this is the issue, clean your MAF by soaking in tape head cleaner (or replace it).

i doubt if this is your evo. do you have the capability to post the long and short term fuel trims from your OBDII scanner? if so, post them; they will help determine if the rich threshold is breached on long term trim or on short term trim.

[Pez]

Thanks Insite,

Tonight I will recheck the intake and log some settings that are at speed, the settings attached are taken from an idle. This weekend I will try cleaning the MAF with contact cleaner and see if that helps.

Thanks again!

Chris

(sorry for the long post I tried to post it in a excel file but was having problems with it :o )

SHRTFT_1_3(%) ET(sec) LONGFT_1_3(%)

-7.8 21.8 30.5

-8.6 29.44 30.5

-8.6 33.45 30.5

-5.5 37.46 30.5

-7.8

-5.5 71.68 30.5

-6.3

-7.8 122.98 30.5

-5.5 126.99 30.5

-7 131.05 30.5

-6.3 135.11 30.5

-7 141.71 30.5

148.63 30.5

-5.5 152.64 30.5

-9.4 156.7 30.5

-7.8 160.71 30.5

-5.5 164.77 30.5

-4.7 168.84 30.5

-5.5 173.34 30.5

-6.3 177.46 30.5

-7 191.19 30.5

-7 195.2 30.5

-6.3 199.27 30.5

-6.3 203.28 30.5

-5.5 207.29 30.5

-5.5 211.41 30.5

-7.8 215.42 30.5

-5.5 219.48 30.5

-5.5 223.54 30.5

-5.5 227.55 30.5

-3.9 231.62 30.5

-5.5 235.63 30.5

-2.3 239.69 30.5

-3.9 243.76 30.5

-1.6 247.77 30.5

-0.8 251.39 30.5

-0.8 255.4 30.5

0.8 259.47 30.5

3.1 263.48 30.5

2.3 267.48 30.5

3.1 271.49 30.5

3.9 275.5 30.5

4.7 279.46 30.5

4.7 283.58 30.5

4.7 287.64 30.5

[ar38070]

If I read that post of yours correctly your long term fuel trim is 30.5 which means that it is maxed out. This looks like a MAF problem.

P1126 is Oxygen Sensing Adaptation Area 1 (Cylinders 4 - 6) - Rich Threshold

This means that the fuel mixture is as rich as possible. You should be able to smell this. The exhaust will be "sweet" from excess fuel.

As far as I can tell there is no P1133 code.

[Pez]

Thanks ar38070,

The P1133 had me baffled as well, For the exhaust there has not been any noticeable change in the smell, but everything seems to be pointing to the MAF, and I guess I know what this weekend’s project will be..

Thanks for all the advice so far!

Chris