Jeep p0135 code - 2000 Jeep Grand Cherokee Laredo

Some are easy fixes (O2 sensor), the fuel vapour ones need a bit of investigation, as does the Neutral Safety Switch..

P0135 JEEP Code - O2 Sensor Heater Circuit Malfunction ...

https://www.engine-codes.com > p0135_jeep
'P0135 JEEP code possible causes · Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 · Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse · Heated Oxygen ...

P0455 JEEP Code EVAP System Large Leak (With Video)

https://www.autocodes.com > p0455_jeep
May 30, 2020 - 'P0455 JEEP code tech notes ... The P0455 it's very common code because the code is set if the gas cap is loose or missing. Start by tightening ...

P0442 JEEP Code Evaporative Emission Control Small Leak ...

https://www.autocodes.com > p0442_jeep
May 30, 2020 - The P0442 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the ...

P1899 JEEP Code - Park/Neutral Switch Circuit Conditions

https://www.engine-codes.com > p1899_jeep
'P1899 JEEP code possible causes · Faulty Park/Neutral Switch · Park/Neutral Switch harness is open or shorted · Park/Neutral Switch circuit poor electrical ...

P0135=O2 Sensor Heater Circuit Malfunction.
I found a guy that explains it well here's the link.
P0135 O2 Sensor Heater Circuit Mulfunction

Check the wires at the back of the harness plug for any breaks. Some times they break inside the coating, so pull on them. If they stretch, it broke.

kia ora Mark , greetings , sorry bro these code things are beyond me ive been driving around with a p0161. i believe its a bank2 down stream sensor for 2 years , maybe you can help me , 2002 grand cherokee 4.7 Ho , do you know what brand of sensor or part numbers i need , an idea of cost for same . i forgot to mention i am in New Zealand and auto parts are so much more expensive here , no idea at all , much help needed everyone thank you all , hope you get sorted Mark cheers mate

did you google that
type "obd2 p0135"
read that yet, if not clear the words do ask what they mean.
same with 141s.

one more thing to check after going through all this stuff, which actually these guys seem to have a wealth of knowledge on. seriously. jeep for some reason has a notorious situation that so many mechanics and enthusiasts miss. .. it took me 3 weeks to figure this stupid mess out for my x's daughter, who hates me by the way, but i do it because i'm a nice guy. try the cam sensor. sounds silly i know. but i see it more and more as being the answer to all these mysteriousness ailments to these hard running jeeps. my daughter is getting ready to drive and wouldn't you know it she wants a grand cherokee. lol. I have an 87 yj. but its a weekend mustang killer. and i luv to stomp tuners on the highway. its on youtube. got a lil sbc, with a t-5 borg warner hybrid shorty, 1,2,3, fast throw, 4,5. way long. 4:11 rear with detroits. not 4wd. its so fun. had to put upper and lower lakeside drag bars. but anyway..... :) cam sensor give it a thought. sometimes 1 and 2 banks are hard to differentiate for some reason when reading codes. still trying to figure that one out.???

for p0135, you can try this:
Repair short or open or high resistance in wiring harness or harness connectors
Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)

P0134....O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)

P0135....O2 Sensor Heater Circuit (Bank 1 Sensor 1) heater in the O2 sensor has packed up first sensor before the cat

P0305 IS # 5 CYLINDER MISFIRE DETECTED.P0135 IS BANK 1 SENSOR 1 OXYGEN HEATER CIRCUIT FAILURE

O2 sensors are tricky. sometimes like anything else they fail. many times though the exhaust mixture they encounter is out of their range and that shows up as a failure.since you seem to have no other problems , I would go ahead and change them, but don't be disappointed if the code shows up again (at least you know it's not the sensors.) I don't like using the process of elimination when doing repairs but sometimes you must.