B5 Models Please discuss all 1996 - 2001 B5 A4 topics here...

S4 2.7t p1131

  #1  
Old 03-30-2012, 11:41 AM
1st Gear
Thread Starter
Join Date: May 2008
Location: Riverside California
Posts: 14
Cool S4 2.7t p1131

Hi everyone! Happy Friday!

My car started just yesterday started running in limp mode and throwing the following codes:

P1131 - bank2 internal resistance to high
P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2)
P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
P0306 - Cylinder 6 misfire.

Above 3300 on a fairly aggressive throttle, the engine shudders, stutters.

I'm thinking for P0306 I should replace the coilpack or swap from another cylinder to see if it clears 6.

Not sure for the other codes whether I should start by replacing the Front Driver's Side O2 sensor.

What do you guys suggest?

Please help me make my Saturday a better one by helping me fix this AWESOME machine.

G.Thanks.
 
  #2  
Old 03-30-2012, 11:56 AM
1st Gear
Join Date: Oct 2010
Posts: 438
Default

Originally Posted by tannercortes View Post
Hi everyone! Happy Friday!

My car started just yesterday started running in limp mode and throwing the following codes:

P1131 - bank2 internal resistance to high
P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2)
P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
P0306 - Cylinder 6 misfire.

Above 3300 on a fairly aggressive throttle, the engine shudders, stutters.

I'm thinking for P0306 I should replace the coilpack or swap from another cylinder to see if it clears 6.

Not sure for the other codes whether I should start by replacing the Front Driver's Side O2 sensor.

What do you guys suggest?

Please help me make my Saturday a better one by helping me fix this AWESOME machine.

G.Thanks.
Yes for the misfire swap the coil pack with another and see of the misfire switchs on you. If not try new plugs.

The cats on your car are not at the same effiency as before when they were fine. Basically you need new cats. Do you smell any rotten eggs? Changing the 02 sensors won't help. 99 percent it's the cats. But it's a small possibility the 02 sensor is bad.

If you are not having any loss of power or hesitation after you fix the misfire then that's a sign your cats are good. There was a ecu update that I think applies to the 2.7 about tuning down the Ecus requirements for the cats at the dealer.

If that doesn't help code the cats out of the ecu by a tuning company. Then you can gut them or whatever.

Also you can try running spacers on the 02 sensors. That will make the 02 sensor not directly hit the exhaust gases so it can trick the ecu into thinking the Cats are ok.
 
  #3  
Old 03-30-2012, 12:49 PM
1st Gear
Thread Starter
Join Date: May 2008
Location: Riverside California
Posts: 14
Default

Budhani:
Thanks for the reply. As you suggested, I'll start with the coilpack and then the plugs.
If still misfiring, I'll assume cats are gone.

If cats are gone, and I have a tuner ignore them, will I be able to remove or bypass them? I'm a little unclear on options available for handling cats. As well, ultimately, I want to be able to pass emmissions test in the future.

Thanks so much.
 
  #4  
Old 03-30-2012, 01:47 PM
CCA4's Avatar
Administrator
Join Date: Jun 2008
Location: NW PA
Posts: 7,588
Default

Forgive me for being "that guy," but you might have better luck posting your questions in the S4 forum. Not many of the 2.7T experts frequent the A4 boards. JM2C!
 
  #5  
Old 03-30-2012, 06:17 PM
ImTheDevil's Avatar
Administrator
Join Date: Jul 2006
Location: Binghamton, NY
Posts: 11,670
Default

Bad secondary O2s are not uncommon on a B5, and if you're shooting from the hip, replace them (at $60ish each for universals) before dropping a grand or more on cats you may not need. And if it's cat efficiency, it is the secondary O2s, not the primaries, that would be bad.
 
  #6  
Old 03-30-2012, 09:13 PM
1st Gear
Thread Starter
Join Date: May 2008
Location: Riverside California
Posts: 14
Default

CCA4: Thanks for the advise. I'm getting pretty good advice here as well so I'll hold off from posting in the S forum for now but thank you.

ImTheDevil:
Thanks for replying with advice. I read several posts that eluded to the front o2 sensor, related to P1131. You're the first to recommend replacing the secondaries. It does make a lot of sense for the efficiency codes though so I'll go ahead and order those up as well.

Is it possible that the Cyl 6 misfire code could cause efficiency codes to fire?

Thanks a bunch.
 
  #7  
Old 03-30-2012, 09:32 PM
ImTheDevil's Avatar
Administrator
Join Date: Jul 2006
Location: Binghamton, NY
Posts: 11,670
Default

Yes - if you're misfiring your mixtures won't be right so it's possible, but fixing it isn't too likely to clear the efficiency codes. But yeah, cat efficiency is measured by the secondary O2 sensors. The primaries are ahead of the cats so they don't have a clue what the efficiency is like.
 
  #8  
Old 03-30-2012, 09:46 PM
1st Gear
Thread Starter
Join Date: May 2008
Location: Riverside California
Posts: 14
Default

All right. I've ordered up both secondary sensors, 1 coilpack, 1 front o2 sensor (just in case), with discount from Carquest for $504, all OEM mfg.

I hope I don't jack the car up more since it is my only ride and will have to drive all week on it.

On a side note, do you guys recommend running SeaFoam or equivalent through the systems?
 
  #9  
Old 03-30-2012, 09:54 PM
1st Gear
Thread Starter
Join Date: May 2008
Location: Riverside California
Posts: 14
Default

And the spark plugs...
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Turbo123
Audi A6
5
11-18-2011 09:02 AM
Travice00s4
S Car Model Line
1
11-07-2011 09:53 AM
azeezn
Allroad Model Line
6
12-29-2009 12:40 AM
Meatball1974
Audi A6
4
09-23-2008 11:53 AM
bolob5
S Car Model Line
2
06-19-2008 09:17 AM


Thread Tools
Search this Thread
Quick Reply: S4 2.7t p1131


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.