Autolite, Champion, and NGK are three good brands for spark plugs in our Wranglers. Just know to avoid single-tipped platinum (platinum on just one side of the gap) on newer 4.0 engines with the coil rail ignition systems. Conventional, double-tipped platinums, and iridium tipped are good in all model years and engine types. Single-tipped platinums are good in earlier 2.5 and 4.0 engines with a distributor cap and individual spark plug wires.
I doubt I'll ever do 30k miles with the current fuel prices over here hahah at the moment it's costing me £80 to fill which I think works out to be about 110 dollars , it's nuts compared to the small Chevy I had before that took £30 to fill the tank and lasted 250+ miles , but it was nowhere near as fun as the jeep
I am not sure that you have a pcm issue yet. There are no serviceable parts inside of that pcm and the gelled coating encapsulates in the heat until it malfunctions.
Hard to say for sure but if they're Bosch I'd definitely be more than suspicious and immediately replace them with NTK or NGK.
Thanks for your reply mark,
So I've climbed under the jeep today and it appears that only 1 post cat sensor was changed bank2 sensor2 , but it's an NTK one , and the plug is fully seated. The rest all appear to be NTK sensors also. I gave everything a good shake as someone suggested the cat may be loose but everything's snug and tight
With there being a pub on nearly every street in Glasgow, I would find no reason to every need a vehicle while living there.
Aside from the one new O2 sensor the others are the originals. How many miles on your jeep?
Do you think it's possible that the o2 sensors could me failing and just not throwing codes ? I'm guessing the only way to tell would be replacing them and seeing if there's a change. In my post I had said I didn't know if it's was something heat related as it had sat un driven for a while before I got it and I jumped straight in and drove for like 6hrs straight ? So I presume maybe that running for that long when it's not used to long journeys could have tipped them over the edge ?
Thanks for all your help it's been a life saver, I'll try replacing the remaining O2 sensors and see what that does. If nothing else it'll save me doing it in the future anyway.
Make sure whatever O2 sensors you buy are NTK or NGK. No Bosch or store brands.
Yeah I found Chris's post on o2 sensors , I presume export models will all be the same part numbers ? I can't see why they'd need to be different.
Disconnect the battery when you replace the plugs and O2s to reset the computer.
Thanks for the tip, it's really helpful having all this help. As I had said I went from a 2013 Chevy hatch back to the jeep and it needed no maintenance, so having to dive into it so soon it's been a real help having so many people that live and breath jeep on tap. It's just a pain it's a hard to diagnose fault
X2, don't use the special 7/8" O2 socket with the slot milled into it for removing the old O2 sensors. It's not strong enough for that since they are normally seized into place by the time they need to be replaced, it's meant for installing new O2 sensors. Cut the wiring off from the old sensors first then use a normal 7/8 socket/box-end/open-end wrench as needed. You may need some extra leverage from a breaker-bar etc. to break them free, they can be TIGHT.
I guess its one of the joys of owning a tj in a country that grits its roads at the slightest hint of ice haha. The rest of the frame is actually remarkably clean and rust free, just the notoriously bad exhaust that's caught the worst of it. I had ordered an o2 sensor socket, but I had imagined that by the look of them they'd be insanely tight to get loose.
