mehoff_400

i am currently getting both of these codes on my 01 xj.

i just swapped my head out due to cracking of the head.

P0122-TPS sensor
P0155 02 sensor bank 2 sensor 1

i swapped the TPS sensor but no change in the code.

doing some searching on the internet i am not seeing anything about getting both these codes at the same time.

this makes me think its something due to wiring possibly.

currently the jeep idles really rough.

anyone with any experience with this?

mehoff_400

i reset the computer and currently the TPS code has only came back. i only drove it around the block a few times so i'm not sure if it has had enough time for the o2 sensor code to come back

Joshua Blue

Have you checked the connector for damage...sounds elementary I know but you have to ask these type questions. If the connector is ok check for a short in the wires. Trace them back to the firewall and verify that the wires condition are ok (had a shop mess up a wire of mine and it took a while to find it). Do you have a reader that will show a live display?

dave1123

With a head change, it's common to pinch the wire harness that runs behind the head when you put the head back on. Check it out.

mehoff_400

what do you mean by a live display? i just bought a ODB2 cheap reader on amazon.

mehoff_400

couple things i did today.

replaced the TPS sensor with a new one. (replaced it with a used one before)

replaced spark plugs in it with the ones that were in the other head. just in case i had bad spark plugs.

put the stock injectors back in it. replaced the stock ones with rebuilt 4 hole ones.

still seeing the same issue.

i currently dont have a check engine light but borrowed the auto parts store scanner and the TPS error was still coming up.

checked the harness i didnt see anything visually that looked like it was an issue.

mehoff_400

When i replaced the head i didnt rotate each cylinder to TDC before torquing the rockers to spec.

would this cause an issue? i have head of people doing it with going to TDC and not.

97grand4.0

Just did a head change on mine and had idle problems. Ended up changing out the iac motor. Dont know why or if this helps you but anything idle related you have to look at the iac.

mehoff_400

Seems more than idle related. When driving it will slightly back fire. Not as much power as it should. When replaciythe spark plugs #3 had soot black on it. None of the other ones did.

mehoff_400

i did some tps testing today from info here

i am currently only getting a TPS code the O2 sensor hasn't came back

everything to the TPS tested good. its getting 5 volts and ground tested to 12 volts.

TPS has been changed with a used one from a running cherokee and a new one from the auto parts store

https://troubleshootmyvehicle.com/je...sensor-tests-1

mehoff_400

before doing the TPS check i looked at some of the wiring i didnt find anything but i might of not looked good enough

after i did the TPS check i check the engine codes again and got

P0122 - tps low input.

P0123 TPS high input

hmmmm weird.... not sure where to go from here now.

mehoff_400

well to follow up on anyone that comes across this in the future. i think i had a couple things go out at the same time. i replace the TPS sensor and it still ran rough after looking at the dash while it was running i noticed the airbag light was on so i replaced the clock spring and still had the same issue but seemed better so i drove it some more just to see if i could get any different check engine light. when i checked again i got missing on 2 cylinders. in a last ditch effort i have another cherokee and thought maybe the rebuilt injectors i got were bad so i swap injectors from my other jeep to this one and boom runs perfect. i just sent an email to the guy i bought the injectors from on ebay to hopefully send them back to get tested again.