Taking bets on the limp mode problem

[RSS]

So your options are

Symptoms where driving along fine went to pass one car worked fine 3min down the road driving normally went to pass another car now i only get 6-8psi car runs fine fuel mileage has been normal as of late just in soft limp mode.

Bad EGT sensor drivers side
Bad EGT sensor passenger side
Bad 02 sensor driver side
Bad 02 sensor passenger side
Simple boost deviation from MBC coming loose when in parallel with N75
Other

winner gets a cookie i will be pulling codes tonight.

I got a solid 3 drives in my car since i fixed the overboost and now this.

[Mantis]

Re: Taking bets on the limp mode problem

not the 02 sensors, I drove with both s1 sensors fried for about 6 months and no soft limp, EGT is possible, not probable, I am going with a small to moderate boost or vacuum leak. Pull the codes and then get your leak tester out. Have fun

[R-Audi]

Re: Taking bets on the limp mode problem

I agree.. EGT and O2 are doubtful... Im going with vaccuum leak or N75

[RSS]

Re: Taking bets on the limp mode problem

New info as i am eating dinner the car ran perfect on the way home spike 23 hold 21 brought it up to full boost 5 times no issue.

I love problems that dissapear problem is that they always reppear.

[Mantis]

Re: Taking bets on the limp mode problem

Roger, you're no fun to play with

[RSS]

Re: Taking bets on the limp mode problem

Well the codes are in and i don't think cookies are coming your way

16534 - Oxygen(lambda) sensor B2 S1: Malfunction in circuit
P0150 - 35-10 - intermittent

17538 - Fuel Trim: Bank 2 (Multi) System too lean
P1130 - 35-10 - intermittent

[R-Audi]

Re: Taking bets on the limp mode problem

02 Sensor it is...
You still coming on Thursday?

[RSS]

Re: Taking bets on the limp mode problem

Well the probable reason the o2 sensor died was because I was test running my 104 program for thursday! jk or was I? see you then.

[Mantis]

Re: Taking bets on the limp mode problem

Your S4 is a girl, get an A6, they still boost when all 4 02 sensors die

[vee_dubbin]

Re: Taking bets on the limp mode problem

16534 - Oxygen(lambda) sensor B2 S1: Malfunction in circuit
P0150 - 35-10 - intermittent

17538 - Fuel Trim: Bank 2 (Multi) System too lean
P1130 - 35-10 - intermittent

O2 sensor won't cause your driving issues, although your mileage will be screwed. But the code also mentions that its sporadic. This sporadic fault in your O2 sensor could be caused by the fuel trim-too lean code.

The Fuel trim- system too lean is caused by the Mass Air Flow sensor 98% of the time. This could throw off your ECU, therefore reducing boost because it thinks that the mixture is too lean and it doesn't want you to blow the engine under normal boost pressures. Another cause could be a vacuum leak somewhere. But my bet is on the MAF.

If the problem ends up being a bad MAF sensor, can I have the cookie?

[RSS]

Re: Taking bets on the limp mode problem

cookie is your if it's the MAF

But if the o2 sensor is failing it is the primary o2 so wouldn't that effect my fuel trims say it's reading rich incorrectly it would lean out that bank and cause the other code i do agree that the limp mode was caused by the lean code but the cause from what i have been reading is usually the o2 either way it's going to suck $300 in o2's or 300+ for a new MAF

[The_Jerbel]

Re: Taking bets on the limp mode problem

Vee dubbin is close, it's not the MAF, but soft limp mode was caused by the boost leak (system too lean code).

BTW, if the EGT's or primary O2's are giving drastic enough readings they will also cause soft limp mode.

[RSS]

Re: Taking bets on the limp mode problem

So i had a boost leak that fixed itself?

[The_Jerbel]

Re: Taking bets on the limp mode problem

You said that you had a boost deviation from the MBC coming loose...

[RSS]

Re: Taking bets on the limp mode problem

Those first options where my guesses on the problem i checked it and it seemed to be tight. I did fully open it up just to make sure tho i will run it the next couple of days and see if any of the codes return.

If it was a deviation wouldn't i get a code for that as well?