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well.

bought a R32 gtst bout a week and a half ago. since ive had it it's had a problem to do with what i think is the exhaust temp sensor. basically, if i drive hard for a while, anywhere from 10 mins to half an hour depending how hard im driving, the exhaust temp sensor light comes on and starts flashing.... then when ever i come on boost...round 3 grand...the car will get really sluggish and not feel to good. this will continue until i park and let it cool down for a few hours.

car has stock ecu which has had a remap.

cat has been replaced in the last week

mech said the oxy sensor looked alright...

so i have no idea. would it be better to get the sensor disconnected from the ecu or something? any ideas?

thnks

Gus

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that sensor doesn't go to the ecu. just used to light up the light on the dash. if you dont want the light on the dash to light up you could disconnect it, but you said that the car starts to feel sluggish, is it possible you have something restricting the exhaust, i would have said collapsed cat but you got that changed, maybe something stuck in a muffler?

If your seeing the light flash AS WELL as a change in vehicle behavior, I would suggest that the reason for which the sensor is there, is being triggered; heat. The tune could be not quiet right. A tuner with a wideband could help.

  • 1 month later...

the exhaust temp sensor will go off if the exhaust temp is too high, the main reason for that there is an exhaust restriction creating excessive heat (most likely a block cat as mentioned above).

Take the cat out and see if its collapsed, melted or just blocked full of crap.

EDIT: just noticed you replaced the cat, still take it out though, i've seen brand new cats collapse within a week

Edited by R34GTFOUR
If the cat did not collapse, would it be possible that the new cat is running hotter than the stock one? And therefore setting of the sensor?

Collapsing after a week would have to be a pretty low quality cat...(or a really bad installation)

i wont mention the brand that collapsed, but it was definately not cheap, just a freak manufacturing fault most likely.

A new cat shouldnt run any hotter, if anything cooler since it can flow more. Unless a smaller cat was used = more restriction.

If the cat did not collapse, would it be possible that the new cat is running hotter than the stock one? And therefore setting of the sensor?

Collapsing after a week would have to be a pretty low quality cat...(or a really bad installation)

yeah cat was replaced.

so now no idea...i think it would have something to do with something being blocked but its weird...seems to do it when its hotter temp. i can drive to work in the morning and be fine (light doesn't come on, no spluttering) and then after work when its been sitting in the sun all day...drive for 30 seconds and it will come on.

wtf.

could it have anything to do with sparks or coils? the car is running a bit rich so anything to do with that?

maybe a fkd ecu?

I have this exact problem in my R32 ... has been doing it ever since I have had it ... seems when the light starts flashing it must send an signal to the ECU to limit performance ...

My car goes into underpowered lamo mode when the light starts coming up so it's probably a safety (limp mode) in the ECU...

I gather the sensor because it is placed after the cat converter it measures excessive heat ... in the exhaust ...

If what you are saying is that you replaced the cat etc.. I would be looking at your tune it sounds as though it is running Lean when coming onto boost ... (Lean mix can cause excessive heat in the exhaust hence tripping the sensor)

  • 3 months later...

My 32 gtr lights up for a second when I reach 1.5bar (so only for a second) and then turns off the second I change gears or release the accelerator. It must get momentarily really hot at high boost and then cools down as soon as the pressure is released. However during that period i never experience a limp mode. Maybe because i am running a pfc?

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