Oxygen Sensor??
 

My check engine light came on so I got around to pulling codes....P0030 and P0135. Thought to myself, my gas mileage might not be as good, power doesn't seem to be 100% and I thought I noticed a very minor lag time once or twice when I accelerated from a stop. Decided to replace the oxygen sensor with one I found online. The old sensor looked pretty burnt up. Took the truck out for a drive and when I turned out of the neighborhood and accelerated the RPMs dropped to idle, even after I put my foot to the floor. After 3-4 seconds the RPMs increased and I could get up to speed. This happens almost every time I start from a stop or slow to make a turn. The RPMs don't drop while staying at speed. Was my new oxygen sensor made by a deviant hybrid driving hippie or a chimpanzee imprisoned in an auto parts factory in China? Did I use a left handed socket wrench by mistake?? Help appreciated.

Is it a cheapo Chinese product?
Try using the same quality brand as original.

actron obd2 scanner will show o2 voltage fluctuations from 0-1v. then u know

Drove the truck again and checked it with obd2 scanner. o2 codes were gone and voltage was reading 0.5-0.6v on the sensor. Other codes showed up though, co244 torque malfunction? co268 abs? u1000(After I replaced the o2 sensor I did pull the pcm fuses to reset the engine light)......While I was checking the codes the engine light came back on and p0300(misfire) showed up. Seen that one before, replaced my plugs and coil packs to get rid of it. It seems to come and go.

Am I reading that right, you joined this forum 10/2006?
Wow... You should be educating others by now..

P0300 code is a random misfire detected, which is most commonly caused by fuel or air delivery, and not cylinder specific.

Common issues with the H3:
Intake manifold leak
pcv leak
fuel pump module lines rotted (if you smell fuel)
Maf sensor cleaning
Throttle body cleaning
Fuel induction cleaning
Fuel injector cleaning

GL

1 other thing with all those codes you have showing up, check the pwr/trn relay #81. pull and inspect it..

Replaced the o2 sensor again, this time with a Bosch (51513). Truck ran great, no issues. The other o2 sensor I bought online was junk or not for my truck. Lesson learned.

Cheap parts are cheap for a reason. ;)

My O2 sensor was an unfamiliar brand but I bought it from NAPA auto parts and it seems to be working. I thought I would have to use anti seize spray but when I put the tool to it the thing unscrewed and came out no problem whatsoever.
Trouble codes were P0030 and P0135 also. The truck would lack acceleration until fully warmed up.
It's nice to not have an engine light on all the time. Mine is also a 2006. I thought of trading it in for a new Cherokee but other than a head gasket under warranty, throttle body cleaning and radiator pump replacement this SUV has been trouble free. I heard these models will increase in resale value, not sure how true that is.