Idle Issues

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Aug 24, 2015 | 08:47 AM

rcguymike

Thread Starter

CF Veteran

Joined: Aug 2015

Posts: 1,226

Likes: 11

From: Laurium, MI

Year: 1999

Model: Cherokee(XJ)

Engine: 4.0L

Idle Issues

Sorry to necromance this...but my 5.2L is doing this while costing downhill, I have to replace the downstream o2 sensor do you think that will solve the problem?

Aug 29, 2015 | 09:05 PM

mtoskippy

Junior Member

Joined: May 2015

Posts: 51

Likes: 0

Model: Grand Cherokee

Engine: 5.2l

I would put money on the IAC... Mine did the exact same thing (5.2L TSi)
I pulled my throttle body off, tore it down, cleaned it and replaced the IAC... It came apart when I removed it... The throttle body was caked with oily sand and soot... Idles like silk now... and no more RPM floating like that...

Last edited by mtoskippy; Aug 29, 2015 at 09:21 PM. Reason: grammer

Aug 29, 2015 | 09:33 PM

dave1123

Old fart with a wrench

Joined: Nov 2010

Posts: 14,398

Likes: 740

From: Manlius, east of Syracuse, NY

Year: 2000 XJ Sport & WJ Laredo

Model: Grand Cherokee (WJ)

Engine: 4.0L

The only function of the downstream 02 sensor is to monitor the function of the cat and doesn't effect the mixtures in any way. If go with the throttle body cleaning and replacement of the IAC. Replace the base gasket as well.