What is the proper way to remove and install O2s when fitting a after market cat back exhaust using the existing O2s, do you unplug the connector or just twist the wires to fit, just interested because I was just having a look at mine and one side wires are still twisted ,the other side is good, your thoughts please cheers. Ps the exhaust was fitted by a "professional exhaust place and the idiot CUT the outer Guard off because he said the O2 socket was splaying out " why didn't he use a little bit of heat ?? for stuffs sake I am a mechanic with a bad back and 58years young, but I haven't a hoist, doesn't anyone take pride in there work anymore RANT OVER.

 

I just spray mine with some pb blaster a few minutes before I put a socket on them, then carefully break them loose. I don't think you need to disconnect the plug beforehand as long as you are careful. When installing, I put a small dab of anti-seize on the threads and I pre-wind them counter-clockwise so that when they are tight the wires are mostly straight and not twisted.

I don't understand what splayed out means but the shop should not have cut the shield off the sensor. I assume it is there for a good reason other than to make it more difficult to remove.

 

Yep they cut the outer shields off because the proper long socket was opening up they were very tight but FFS they could have put a bit of heat on them and WD, but one side wires are still twisted and they are fully installed, so this might be why I am getting a CEL coming up every 350kms to me I think they butchered the O2s, when the Cel comes on again I will see them and blow the sh#t out of them very diplomatic though, they are 2kms away from were I live and I pass the shop every day and GROWL GRRRRR. When I was under the car today the bolts on the front cats were the Xforce bolts up were 1 turn loose. GOD I wish I had a hoist at home, sorry ranting again but I hate bad workmanship especially when you are a very good mechanic but my back if f#cked thank CL.

 

I think you've found your problem right here. As I posted in you're other thread, I bet the cel is from the o2 with the twisted wire. There's a thread floating around here from joe-z where he's found this to be a common issue for our cars. The sensors are super sensitive so if left twisted, it'll throw a code.

Your shop should have either unplugged or pre-twisted counterclockwise before reinstalling. Straighten them out (shop and wires ) and report back.

 

The O2 sensors will also throw a code if there is a leak where the manifold meets the new exhaust piping. I don't know what gasket the shop used when they installed your exhaust, but I know from having three different exhaust systems on the car that it can be a little tricky to get everything sealed properly on the first shot. I would recommend torquing the bolts to spec, then get the system heated up for a while and checking the torque spec a second time. When I installed my first exhaust, I tightened the x-pipe to spec and after driving it for a day the bolts were barely hand tight.

 

my CEL was on this morning when i went to the gym, but when i started the car after it was off LOL. not sure if good thing or bad, but I'm going to still run codes and get the O2 sensor wires, etc. there's a thread here on which gaskets to use from manifold's to mid pipe, the shop shouldn't have reused the original OEM ones, unless you didn't supply new gaskets. I haven't removed an O2 sensor in years, but i've never had issues just using an open end wrench, O2 sensor tool is ideal though.

 

You won't get a wrench on these. They have shields around them to protect from water intrusion by splashing. Won't fix driving through standing water, but will prevent the bulk of O2 efficiency DTCs. The shield ensures it will be impossible to get them out without an O2 sensor socket. The socket splays because it has a slot for the wires and does not continuously surround the drive surface for the tool on the O2 sensor.

The service manual says to twist the wires before installing so they are neutral once the sensor is installed. Twisted will cause noise since you have the heater current and the signal wound up causing interference on the signal side. No matter how you do it, just be sure the wiring is not twisted when you are finished.

 

understood Lance. i'll check my wires to see if they are ok and go from there. CEL back on.

 

Hey Lobux did you read my second post here like I said blo#dy butcher this exhaust bloke with30 years experience, some people don't learn or don't care I will be seeing him shortly, if he has stuffed my O2s it will get very messy thanks again will let people know on the out come.

 

I saw it. Some people never learn. I spent a lot of time on the DIY-EFI project around their wideband sensor kit during which I learned a lot about how O2 sensors work - both narrowband and wideband - so I may have 40 years of engine building, but I'm not mired in the past with my approach to problem solving. I cut my teeth on carburetors, but realized fuel injection was the future way back in the 80's. I've spent a lot of time developing an understanding of how it works...

 

Yep took it back and no O2 codes just cat codes this bloke is thick I explained that the Xforce delete the second cat and I Said I will put O2 extenders in and see if that works, he Said good idea, o boy they live amongst us, this is the 30 years experienced bloke who installed the exhaust OMG someone save me.