bewilderedbeast
NAXJA Forum User
- Location
- Seattle
96 4.0 AX-15 5-speed. 132K miles.
All relatively new(within a year):
Plugs
Wires
Air Filter
Serp Belt and Idler pulley
Water Pump Transmission Fluid
Has always run exceptionally well, never any issues.
Replace bad Oxygen sensor at about 50K miles.
A rattle developed underneath about a year ago, only at certain rpms, usually at idle and when just starting to roll in 1st gear. I figure it was either a loose exhaust clamp or maybe the cat. Never worried much.
Lately it's gotten much worse, but is intermittent. A friend diagnosed it as the cat's substrate being cracked. So I planned to replace it. Still no driveability issues.
A couple of weeks ago it threw an engine code--2-1 for the o2 sensor. The light went out after a while, but the code remains in memory. Still no difference in the driving. No stumbling, no sputtering, engine smooth and quiet(for a Jeep).
The past few days I notice when driving on slight inclines on the freeway in 5th gear, I have to floor the pedal to maintain speed. The engine roars like they do, but no racing rpms , no surging, just feels like it's under a big load. Never happened before, always accelerated quickly and easily, even in 5th gear. Tonight I stood on the pedal and ran through the gears, and in each gear, it reaches a point where it's just making noise, not gaining much speed until I upshift.
I did the driveway test for clutch slippage, put it in 5th and locked the brakes, then let the clutch out. The engine died immediately, like it's supposed to, so it doesn't seem to be the clutch. There's no racing of the engine.
Could this be the 02 sensor, even with the engine running as smoothly and quietly as ever? Or the cat? I did notice the exaust from the tailpipe seesm to be hotter than normal, though maybe I don't really know what normal should be, since I don't usually feel the exhaust air from the pipe very often.
Any ideas would be appreciated.
Thanks.
All relatively new(within a year):
Plugs
Wires
Air Filter
Serp Belt and Idler pulley
Water Pump Transmission Fluid
Has always run exceptionally well, never any issues.
Replace bad Oxygen sensor at about 50K miles.
A rattle developed underneath about a year ago, only at certain rpms, usually at idle and when just starting to roll in 1st gear. I figure it was either a loose exhaust clamp or maybe the cat. Never worried much.
Lately it's gotten much worse, but is intermittent. A friend diagnosed it as the cat's substrate being cracked. So I planned to replace it. Still no driveability issues.
A couple of weeks ago it threw an engine code--2-1 for the o2 sensor. The light went out after a while, but the code remains in memory. Still no difference in the driving. No stumbling, no sputtering, engine smooth and quiet(for a Jeep).
The past few days I notice when driving on slight inclines on the freeway in 5th gear, I have to floor the pedal to maintain speed. The engine roars like they do, but no racing rpms , no surging, just feels like it's under a big load. Never happened before, always accelerated quickly and easily, even in 5th gear. Tonight I stood on the pedal and ran through the gears, and in each gear, it reaches a point where it's just making noise, not gaining much speed until I upshift.
I did the driveway test for clutch slippage, put it in 5th and locked the brakes, then let the clutch out. The engine died immediately, like it's supposed to, so it doesn't seem to be the clutch. There's no racing of the engine.
Could this be the 02 sensor, even with the engine running as smoothly and quietly as ever? Or the cat? I did notice the exaust from the tailpipe seesm to be hotter than normal, though maybe I don't really know what normal should be, since I don't usually feel the exhaust air from the pipe very often.
Any ideas would be appreciated.
Thanks.
