tonster799

I jacked up the car and I can locate all the sensors but I want to know how I can remove the sensor along with the plug and put in the new one. The wire seems to run through all middle all these stuff and I'm puzzled as to how to thread the wire/plug in/out. Do i have to remove the cat to replace the sensors? If so I have another problem because the cat runs all the way to the exhaust manfold and those three bolts seem inpossible to reach, especially the ones on the passenger side. Any advice, tool recommodation, pictures would be greatly appreciated. BTW, I have a 98 A4QT and the cat on each side is one long piece.

E Vader

.........coolant resivour. The clip that maintains the wire is underneath it. You do not even need to diconnect the hoses. Just undo the three screws that hold it down. With the cap still on just lift it out of your way.

Now that it is out of your way look directly at the firewall underneath the resivour. Trace the O2 line back to the appropriate clip and undo it.

The cat is another story. You may find that you will need to undo the DP tranny mount after undoing the lower set of bolts (the ones from the Cat to the DP). This was necessary for me in rder to gain manoverability when taking it out of the engine bay as well as repositioning my test pipe. After you have removed one set of bolts, the lower first is how I did it, be sure to support the Cat as it is very heavy and may cause undo stress on the remaining bolts attached to the turbo. Also, reinstall the same way. The alightment at the turbo site is more crutial and has less give than the DP so reattach your test pipe/high flow cat in that process.

Take you time and do it right............you will be happy you did..........happy modding.

tonster799

without any "hard" work, the back ones are the ones I'm concerned about especially threading ethe wire and stuff. I guess I have to if undo-ing the dp tranny mount will help with the cat uninstall. thanks.