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Author Topic: 02 Sensor Issues After downpipe & map  (Read 341 times)

Offline NorthWest

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02 Sensor Issues After downpipe & map
« on: November 09, 2021, 07:14:52 pm »
So had my standard down pipe removed and fitted with a 3inch down pipe from turbo back to res.
as normal and expected the cel light came on after about an hour of driving home!

Had the car mapped on dyno 2 days later. Ill acttach a copy of print out to see what ye guys think.  Tuner mapped car with engine light as normal and went off (happy days). As I was leaving it came back on again ! went back he scanned it and getting a 02 sensor fault. he said must be faulty but seems very sus that its all of a sudden faulty !?

anyways... Cel light now currently back on at home again. Scanned it my self with 'Carly OBD' getting fault code P0030 ( Oxygen (Lambda) Sensor B1 S1: Heating Circuit, Malfunction / Open Circuit ) on vw codes.

ive ordered an 02 spacer 90degree elbow to see if it'll help with cel?

any further suggestions? Take a look at the print out see what ye guys think. Its my first GTI and tune ! novice really  :jumpmove:

Cheers lads !!




Offline rich83

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Re: 02 Sensor Issues After downpipe & map
« Reply #1 on: November 10, 2021, 10:00:19 am »
Don't use a spacer. Buy a genuine Bosch sensor. They do fail, mine did a year or so ago.

Those torque figures are nonsense too. No way it's making 440ftlbs
« Last Edit: November 10, 2021, 10:02:56 am by rich83 »

Offline NorthWest

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Re: 02 Sensor Issues After downpipe & map
« Reply #2 on: November 10, 2021, 10:40:52 am »
Which one will I replace mate? The primary one or the secondary one ?

That’s what I thought . It’s huge numbers like .  By looking at the graphs it is a big jump but I agree with you for sure !

Offline rich83

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Re: 02 Sensor Issues After downpipe & map
« Reply #3 on: November 10, 2021, 11:36:14 am »
B1... bank 1? So it will be the one at the back of the engine before the cat.

Offline bobby_fodge

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Re: 02 Sensor Issues After downpipe & map
« Reply #4 on: November 10, 2021, 11:53:40 am »
These figures are from Rtech's website site showing what you can expect at each level of their map, hardware dependent of course.

Stage 1 custom remap             240-255 hp        280-310 lbft 
Stage 2  custom remap            265-275 hp        290-330 lbft
Stage 2+ custom remap           275-290 hp        355-360 lbft
Stage 3  custom remap            330-350 hp        350-370 lbft  (k04 or k03 hybrid setups)

Offline briank213

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Re: 02 Sensor Issues After downpipe & map
« Reply #5 on: November 10, 2021, 05:12:34 pm »
Don't use a spacer. Buy a genuine Bosch sensor. They do fail, mine did a year or so ago.

Those torque figures are nonsense too. No way it's making 440ftlbs
I agree with him they put a spacer on my car it completely messed my car up cause the ECM uses the information from O2 sensor to control the fueling on the car especially the one near the turbo that's the bank 1 sensor. After replacing the O2 sensor with Bosch one and removing the spacer all the issues I had on car went away and now my car is running strong making 247 hp and 283 ft.lb torque at the wheels

Offline briank213

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Re: 02 Sensor Issues After downpipe & map
« Reply #6 on: November 10, 2021, 05:16:21 pm »
Don't use a spacer. Buy a genuine Bosch sensor. They do fail, mine did a year or so ago.

Those torque figures are nonsense too. No way it's making 440ftlbs
The torque is way to high for stage 1 tune with dp and intake with my Apr stage 1 tune my car made 283 ft.lb at the wheels.

Offline Pudding

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Re: 02 Sensor Issues After downpipe & map
« Reply #7 on: November 12, 2021, 05:35:50 pm »
Just to clarify on the O2 sitch.....

B1-S1 = Primary sensor.  This one does all the fuel adjustments. Fitted in the downpipe upstream of Cat 1.
B1-S2 = Secondary sensor. This one measures catalyst efficiency. Fitted in the exhaust downstream of Cat 2.

B = Bank.  B1 and B2 refer to the cylinder bank number, so the TFSI will only ever have B1.  R32, V6 and V8s will have B1 and B2.
S = Sensor.

Never, ever fit a spacer to B1, S1.

If you really must use one, fit it to B1, S2.

All decats will trigger a B1, S2 catalyst efficiency fault code and a CEL. 

Some Stage 1 remaps will also cause the same, but not always immediately.

Stage 2 and above remaps code out B1,S2 completely.

B1,S2's job is to make sure the cats are doing their job, but since it's downstream of BOTH cats, you don't know which one is buggered. A bit of a sh1t design really.

Not sure what's going on with that dyno plot, it just looks weird.  Might have been an early run trying to dial in the N75.  That is one humungous boost spike.  Piston cracking cylinder pressures if that number was legit.






2007 ED30 | 2009 TDI 140

Offline NorthWest

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Re: 02 Sensor Issues After downpipe & map
« Reply #8 on: November 15, 2021, 11:25:37 am »
cheers for clearing up 02 topic mate appreciate it !!

in regards to map..I contact the company who done it. he has good reputation over here in the republic!

He said the torque figure was measured in n.m . converts to 323 foot pound on google?