The check engine light came on in the Jeep the other day. I took it to the shop to get the codes read and was told that all 4 O2 sensors were testing bad. Extended warranty covered all parts/labor, but I guess I'm wondering if anyone has ever heard of all 4 sensors going bad at the same time. The tried telling me it's because they get wet repeatedly when driving through flooded streets, etc. For some reason, I think there's more to what's going on with the KJ.

2005 Sport 4 wheel drive, almost 39,000 miles on it, running Heet when the temps are below 20 degrees (I had an old car that used to freeze up all the time, which started the habit of adding Heet). Is it possible the Heet is doing something to the KJ? Or are there any other reasons for this?

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2005 Liberty Sport 4x4

Frankenlift; Skink Sliders; Skid Row front skid; Mopar trans, t-case, and gas tank skids; f/r recovery points; Cobra 75 WX ST; Renegade light bar; hardwired radar detector; 245/75 Guard Dog MTs; Optima Red Top, Amsoil air filter

The Heat is what killed your O2 sensors and your cats will fail soon also.The biggest cause for bad O2 sensors is they are not really bad but the heater circuit starts failing and you get codes for poor O2 sensor performance.

So if I stop running Heet now - will my cats still fail, or is it possible that I can avoid this happening?

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2005 Liberty Sport 4x4

Frankenlift; Skink Sliders; Skid Row front skid; Mopar trans, t-case, and gas tank skids; f/r recovery points; Cobra 75 WX ST; Renegade light bar; hardwired radar detector; 245/75 Guard Dog MTs; Optima Red Top, Amsoil air filter

I have been getting O2 sensor heater codes too. Now I have to get another set lengthened for my setup since i have my 1st smog check due in a few weeks. Ugh.

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99 TJ
71 C101
04 KJ
03 SFA KJ Sport
LOST JEEPS So-Cal

I maybe to late.Has your MPG's and power been lagging lately?

Stuff like Heat and those injector cleaners should not be used often,maybe once every 6 months at max.They are "cat" safe and "O2 sensor" safe but will harm them if used in every tankfull.

MPG hasn't really dropped, but power has been a little less than enthusiastic. I was hoping that the power drop was due to me adding a thicker engine skid and the hi-lift. Maybe I'm SOL thoughv Anyone know if the cat's covered under an extended warranty?

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2005 Liberty Sport 4x4

Frankenlift; Skink Sliders; Skid Row front skid; Mopar trans, t-case, and gas tank skids; f/r recovery points; Cobra 75 WX ST; Renegade light bar; hardwired radar detector; 245/75 Guard Dog MTs; Optima Red Top, Amsoil air filter

They are covered under a 8year/80,000miles federal warranty.

I would not mention using the HEET when you take it in,

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited