mrk01wj

hello, just joined.
I have had my 2001 GC 4.7L limited for 6 years now and love it as my daily driver.
A few months ago it started to intermittently drop rpm and idle roughly in and out of gear. When it was acting up it would not accelerate and sputter, then suddenly recover and take off. I have also noticed a slight loss in power.
I have checked for vacuum leaks with propane. none found.
I have replaced the IAC and rough idle became less frequent.
2 days ago I ran to the store and it was fine. I was in the store for about 15 minutes. When I attempted to start it it would not start unless I gave it half throttle. I had to stay on the gas to get it to run. Run is an overstatement, it was shaking and knocking violently. When placed in gear it stalled, I had to power brake it all the way home.
I have a scan tool and have not had the chance to read codes yet. I will update you when I have read the codes.
Does anyone have ideas or a direction to head in?
My first thought was catalytic converter clogged/ bad O2 sensors.

mrk01wj

Sorry forgot mileage, 175K.
It is also a QuadraDrive.

mrk01wj

Ran a scan today.
Read codes

P0304 Active

Cylinder 4 misfire

P0301 Active

Cylinder 1 misfire

P0300 Active

Multiple cylinder misfire

P0302 Active

Cylinder 2 misfire

P0152 Active

2/1 Oxygen sensor shorted to voltage

P0051 Active

2/1 Oxygen sensor heater circuit low

P0455 Active

Mad Pup

I recently took delivery of a 2004 Jeep GC WJ Laredo V8 that ran absolutely horribly, with misfires, coughs, and intermittent rough idle. After swapping out the crankshaft sensor with a cheap $15 crankshaft position sensor, this truck runs smooth as a Swiss watch. Now I fully understand that cheap Chinese replacement sensors don't offer anywhere near the longevity of Mopar OEM parts, BUT, these eBay sensors do come with a one-year replacement guarantee, which isn't bad for a $20 part, considering that the factory version can run close to $100

The usual suspects to replace in sequence when a Jeep runs roughly are (1) The IAC motor, (2) The Camshaft Sensor, and (3) The Crankshaft Sensor. For $100 or thereabouts, you can snag TWO each of these sensors from eBay. For Mopar replacement part devotees who recoil from the notion of installing cheap Chinese parts in their Jeeps, please bear in mind that quite a few OEM Mopar components are actually made in China under license, albeit perhaps to within tighter tolerances than their unlicensed equivalents made in the same place.

Very Red XJ

Have you checked for frayed wires? The O2 sensor wires running up to the wiring harness can get dislodged and fall against the exhaust header that burns the insulation off causing a short