Topic: 02 sensors...

[Jeffy]

Well I finally got around to seeing why my Jeep has been acting up.  A few days after that 6000rpm missshift the Jeep lost a lot of low end power and the gas mileage tanked several points.  At first I thought it might have been the cat, since it felt the same as when there is very little backpressure. Well, I took the exhaust apart and check and it was fine.  So I go and check for CEL codes.  There was never a light but low and behold, there is a Code 21.  That's for the o2 sensor.  I had just replaced the sensor last summer for CA SMOG and it was around $50.  I can't find anything on a warranty from the place I bought it (Pepboys) or the Bosch website.  I called the local store and the guy looked it up and said there wasn't any warranty and to check the Bosch website.  Then I called the Corporate and they jsut directed me to the General Manager of the local store who looked it up and added that they have it for $76.

I've tried calling Bosch with no luck what so ever.  They are always busy.

I did some searching and it seems that there is a 1 year warranty but no hard proof is available.  I saw that Partsamerica.com (Kragen/Checkers/Schuck's) has the same Bosch o2 sensor for $43 with a 1 yr mfg. warranty.  There are some on ebay.com that are $40 shipped.

Anyone have hard evidence with the Warranty?  I'd hate to buy another o2 sensor since I just bought one several months back.

Looked some more and found this: http://www.boschservice.com/NR/rdonlyres/6C942818-5E37-48E0-B3AF-49C25D0C7B56/0/WarrantyPolicy07.pdf

If it falls under any of these then it does have a warranty.

Automotive Electric, Non-Automotive Electric,
Heavy duty Electric, Electronic Gasoline Fuel
Injection, Diesel Fuel Injection Pumps, Filters,
Timing Devices, EDC System Components,
Nozzle Holder Assemblies, Holders and Nozzles

Any other options?

[wrangler387]

I'd double check the wiring before buying a new one.. It most likely isn't the wiring, but maybe you'll get lucky. I just dont see how your mishap could have messed up the o2 sensor.

[Jeffy]

I'd double check the wiring before buying a new one.. It most likely isn't the wiring, but maybe you'll get lucky. I just dont see how your mishap could have messed up the o2 sensor.

The only thing I can think of is that the engine revved and dumped a bunch of fuel into the cylinders which may or may not have been burnt.  The PCM is supposed to retard the timing as it climbs to around 5600rpm.  Maybe the unburnt fuel caused problems?  Otherwise, it was going to die and it jsut so happens it start right afterwards.

[wrangler387]

i dont think that the unburnt fuel will really kill the o2 sensor like that... Think of how many people have launch control where it is ignition cut to hold the rpms, or rev limiters that just cut ignition only. You may have just got a defective o2 sensor... did you unplug your battery or pull the ecm fuse? maybe it just triggered the o2 code because it was sensing a rediculously rich mixture when you went to 6000rpms...

[Jeffy]

i dont think that the unburnt fuel will really kill the o2 sensor like that... Think of how many people have launch control where it is ignition cut to hold the rpms, or rev limiters that just cut ignition only. You may have just got a defective o2 sensor... did you unplug your battery or pull the ecm fuse? maybe it just triggered the o2 code because it was sensing a rediculously rich mixture when you went to 6000rpms...

It's been months and many starts since that happened.  I didn't bother to check the CEL until today.  I pulled the o2 out and wiped it off with some WD40.  Then I disconnected the battery.  I'll go drive it and see if it reset completely.

I could easily tell the power was down as well as the engine sounded a bit louder then normal (rougher perhaps).  I monitor gas mileage and that was off, too.

[Jesse-James]

A friend of mine had an S10 that was going through o2 sensors and it turned out to be the computer frying them. Just a thought.

[Jeffy]

A friend of mine had an S10 that was going through o2 sensors and it turned out to be the computer frying them. Just a thought.

Well the first one was circa 1992 so I think it was up for replacement.  The new one might just be a fluke.  At least I hope so.  These sensors are cheap and even with the high price they aren't precision watches.  I have to get it on the road and see if it throws the CEL again though.  PITA but still fairly cheap.

I don't drive the Jeep that much since I split driving duty between a Blazer and my Jeep.