o2 sensor HELP!!!!!!!!

Reply Subscribe

Thread Tools

Search this Thread

May 5, 2013 | 03:48 AM

scott_99xj

Thread Starter

Newbie

Joined: Nov 2012

Posts: 17

Likes: 0

From: South of Austin

Year: 1999

Model: Cherokee

Engine: 4.0L

o2 sensor HELP!!!!!!!!

I have 99 xj 4.0L 3-in with new header, pipe's, cat, and flowmaster cat back, new o2 sensor's. The problem I am having is my fuse for the o2 heater keeps getting blown! What could cause this to happen? I traced the wires and did not see any damage/burned marks on the wires. I can drive it for a couple of weeks and its fine then out of know where my check engine light comes on and the fuse is blown. Any advice would be great.

May 5, 2013 | 03:54 AM

freegdr

CF Veteran

Joined: Mar 2010

Posts: 47,923

Likes: 38

From: Broward County Fl.

Year: 1989 xj sport 2dr

Model: Cherokee

Engine: 12 hole bosch Injectors

does fuse blow if senors unplugged ?

May 9, 2013 | 12:27 AM

scott_99xj

Thread Starter

Newbie

Joined: Nov 2012

Posts: 17

Likes: 0

From: South of Austin

Year: 1999

Model: Cherokee

Engine: 4.0L

Quote:

Originally Posted by freegdr

does fuse blow if senors unplugged ?

No I have not tried that yet. What does unplugging them help/tell me?

May 9, 2013 | 05:43 AM

mikesignal

Senior Member

Joined: Aug 2009

Posts: 914

Likes: 14

From: north carolina

Year: 2000

Model: Cherokee

Engine: 4.0

see if it blows without the sensors, then plug them in one at a time, and check the fuse. try to narrow it down to a particular sensor.

Jul 22, 2013 | 08:25 PM

Phoenix77333

Newbie

Joined: Jul 2013

Posts: 2

Likes: 0

From: Fort Collins, CO

Year: 1999

Model: Grand Cherokee

Engine: 4.7 L PowerTech V8

Hey guys I am having the same problem on my 99 WJ. Replaced the fuse thanks to this forum

and reset the Check Engine Light (CEL). It passed emissions thank God, but the CEL came back on this morning, checked fuse and it was blown again. Wiring looks good and O2 harness is not melted, Any ideas?