Sully008
05-30-2023, 12:33 PM
Hey everyone,
Not sure how to explain this, but I’m having an issue with my car that popped up late last year before I put it away for winter. It’s come back now that I’m driving it again.
Usually, when I first start the car, everything’s fine. Fuel pressure is good, oil pressure good, temp good, idles fine.The car sounds and runs great. But after driving for ~10-15 mins., the exhaust note changes, it gets deeper, the car feels sluggish, and it almost sounds like there might be an exhaust leak happening. Also a bit of rattling from somewhere under the car that I haven't been able to pinpoint. Doesn't matter outside temp either (started doing it late fall, still does it now with warm weather).
All vital signs engine wise still appear normal (as noted above). The engine itself sounds fine. No weird noises, no stumbles, misfires, etc.
I’m leaning towards bad/plugged catalytic convertor, or bad o2 sensors, as the car is exhibiting some of the symptoms of those, but I’m not sure…
I did maintenance this spring (new plugs, changed oil, filter, cleaned air filter, cleaned MAF sensor). Did a full change of transmission and rear gear oil about 3 years ago.
The car’s been s/c’d for the last 13 years, almost 95K kms. on it. Magnaflow hi-flow cats have been on for at least 10 years, original stock o2 sensors.
I have the Xcal3 that came with the Trilogy that I could data log with, but what should I be monitoring? If you need more info, please don't hesitate to ask.
TIA,
Not sure how to explain this, but I’m having an issue with my car that popped up late last year before I put it away for winter. It’s come back now that I’m driving it again.
Usually, when I first start the car, everything’s fine. Fuel pressure is good, oil pressure good, temp good, idles fine.The car sounds and runs great. But after driving for ~10-15 mins., the exhaust note changes, it gets deeper, the car feels sluggish, and it almost sounds like there might be an exhaust leak happening. Also a bit of rattling from somewhere under the car that I haven't been able to pinpoint. Doesn't matter outside temp either (started doing it late fall, still does it now with warm weather).
All vital signs engine wise still appear normal (as noted above). The engine itself sounds fine. No weird noises, no stumbles, misfires, etc.
I’m leaning towards bad/plugged catalytic convertor, or bad o2 sensors, as the car is exhibiting some of the symptoms of those, but I’m not sure…
I did maintenance this spring (new plugs, changed oil, filter, cleaned air filter, cleaned MAF sensor). Did a full change of transmission and rear gear oil about 3 years ago.
The car’s been s/c’d for the last 13 years, almost 95K kms. on it. Magnaflow hi-flow cats have been on for at least 10 years, original stock o2 sensors.
I have the Xcal3 that came with the Trilogy that I could data log with, but what should I be monitoring? If you need more info, please don't hesitate to ask.
TIA,