Car forgets it's been tuned!

[s3tby]

I own a 1.8T BEX which isn't throwing any codes or reporting anything in VCDS.

Around 9 months ago I had it stage 1 Revo tuned and I was very happy with the results. I have however slowly realised that now and again the car seems to forget that fact.

From cold (though I am careful until the engine is up to temp), and for as along as I'm scooting around town the (extra) power is always there when I want it. 100% reliable.

What I've found is, if I've been on a motorway journey, say 20 miles, cruising at 70, around 20% of the time when I start to navigate roundabouts etc coming off the motorway, the car feels standard again, and it stays that way until I turn the engine off and get back in for the return journey -then I get my power back.

As I say this is a intermittent thing but only ever happens (if it does happen) after a motorway cruise at constant speed.

Is it time for me to get a smoke test done, even though it's 100% reliable on short / stop start journeys?

Thanks for any replies!

 

[Broken Byzan]

Limp mode. Have you had the car scanned for codes. That should point you in the right direction

 

[GeoffDunk]

Limp mode. Have you had the car scanned for codes. That should point you in the right direction

Did you actually read the original post Byzan?

 

[Broken Byzan]

Excuse me. I missed that. No need for the snarky reply.

 

[GeoffDunk]

Excuse me. I missed that. No need for the snarky reply.

Sorry buddy, there was meant to be a smiley face on the end of that. :thumbsup:

 

[s3tby]

Bryzan Pics had a good point!!! I rescanned again this morning . Sorry guys.

Got this reported back to me...

17522 - Oxygen (Lambda) Sensor; B1 S2: Internal Resistance too High
P1114 - 008 - Implausible Signal - Intermittent
Readiness: 0000 0000


Does that sound conducive to solving my problem given the symptoms as above..? I deleted the code though I guess it will come back. I did change my valve cover gasket recently and figured I might have knocked it, though I don't think I did.

 

[s3tby]

Oh and is that enough to put the car into limp mode? -thanks again

 

[s3tby]

For the benefit of the thread:

S2 is the rear O2 sensor which just reports on the cat, doesn't effect performance (?) though could effect emissions.

The B6 A4 has two of these sensors, S1 is the one in the engine bay.

You need a oxygen sensor socket to get the sensor off -£6, eBay.

"Resistance too High" suggests it could be an wiring or plug issue (open electrical circuit). Worth trying to clean up the connector or check wiring hasn't frazzled on the exhaust first.

S2 sensor on rear of car just after cat, need to jack up the rear (when cold) to replace.

 

[docurley]

This may be as simple as a doggy coil pack or air leek or the O2 sensor playing up either with a doggy sensor or the loom being faulty.

Check connections for coil packs and O2 sensor and double check the spark plugs are screwed in correctly