Every once in a while lately my car suddenly loses power and starts popping and crackling from the exhaust like it is running very rich. This usually happens at an inopportune time where craning down to read the STFT from my Altel reader is not possible without causing a 6-car pile-up. Nursing the engine to a higher rpm generally clears it in a matter of seconds, and everything tends to be fine after that until the next occurence.

It was kind enough to do it at a good place yesterday, and my STFT on both banks were at or over +65!

I ordered a new FPR as a cheap and easy "let's try this", but thought I'd ask if anyone has another BTDT suggestion.

Thanks!

 

It wants to be a F type? Sorry to hear, sounds like a serious problem. I couldn't resist.

 

More fuel added means there is way too much air, unless something really weird is happening. Easiest/cheapest thing to try is look for a vacuum leak. Worth a shot...

 

Vacuum leak is normally a good suggestion. This is something different as it selectively chooses when to go wonky on me.

When it is running right, STFTs are spot-on.

 

Surprised that no codes came up.

 

So unrepeatable means probably can't manage to flag a code - but might manage to flag a pending one. (Maybe.)

Sounds like it's getting a reading that makes it try to add fuel, but which sensor & why (loose connection? chafed wire?).

 

I do get a p0303 and p0304 but those appear after the event.

 

-Coolant temperature sensor issue, could be due to low coolant, air in the system, or a leak onto the wiring.
-Vacuum leak
-Weak coil

 

I was also considering the CTS or IAT as culprits, leaning more on the CTS. I wish I had checked those readings during the last episode.