Ok here we go i have been chasing this problem for a few months now!
First i have a 98 xj both my o2 sensors unpluged as of right now.

So when i have everything all pluged in i can let it idle till it warms up and then it starts to bog down to like 300-500 rpm and shoots back up like a surge of gas but then it goes back down to 300 and surges back and forth. If i hit the gas it will be fine for a min and back to ****! When i shut it off and turn it back on it will run fine for a lil while.

When i am driving it does the same thing but if i hit the gas it will get a big surge and run fine for a while! I also hear a backfire that sounds like it is comming through my intake.

I also not to long ago had my cat removed cause it was blown out. Now its just straight pipe to muffler.

I have replaced:

• IAC
• Map sensor
• coolant temp sensor
• TPS
• Plugs
• Wires

Ok with all that said i have unpluged both of my 02 sensors and it runes fine! No bogging no back fire

Before i unpluged them i had both of them replaced and right after (maybe a few days later) it would through a code for bad o2. Sometimes it would say short to o2 bank 2 sensor.

Please help me i am running really rich and gas is killing me!
Text me if need be!

Mike
734-732-6009

 

What brand o2 sensor are you using?

Is the temp sensor bad? Throwing bad coolant temps to the ECU?

 

I am running bosh o2 sensors
Temp sensor replaced twice to make sure haha!

 

Bump for some help anyone!!!

 

Don't bump.

 

 

Sounds to me like you should put your cat back on and get some new NTK o2 sensors

 

Back firing thru the intake means too much fuel is being dumped into the engine, so it could point to the O2, Also check all the wires for the o2 sensors to make sure they are not shorting to the exhaust or something.

edit: from 1st hand experiance the cat wouldnt affect this unless its clogged, which is smart to remove it temporarily to eliminate that cause.

 

Why not? Need as much help as possible feel like i am chasing a ghost!

 

I have talked to a few ppl and for some reason they are saying cam positioning sensor or crank positioning sensor! Not sure what they are or where they. They sound like the same thing to me!

 

It's a rule

 

Back up... You say your o2 sensor is throwing a code... And it bogs and backfires when the o2 sensor is plugged in... HMMMM!!!

Try rockauto.com. NTK o2 sensors are the way to go.

 

Ok

 

Its also a rule that we do not remove cats, and we do not talk about doing so either.

 

FYI crank position sensor is on the bellhousing on the driver side, should see wires running off the back of the intake down to it. Cam sensor is in the distributor, you'll see the small wires running to it. But I dont think this is your issue. I too have bosch O2 sensors and never had issues but you never know