Do I need O2 sensors?
 

I'm installing OBX LT headers with resonators and a custom tune from PHP. My O2 sensors are seriously rusted into my old headers and I'm not sure if I'll be able to get them out. So, since I won't have cats and have the tune for that, do I need to install the old O2s on my new headers or can I just put a bolt in the hole and not have anything plugged into the O2 connecting wires?

Yes you need at least 1 set of o2 sensors, they tell the computer if the truck is running lean or rich. the second set behind the cat is for emission reasons i think... it senses how efficient the cat is or something like that. your truck will need custom tunes to run without the second set of sensors, but like I said, you definitely need one set for the truck to run right.

Ok. So I guess I do need to really soak them in something like PB Blaster until enough rust comes loose and I can get them out.

I would imagine so... or buy new ones, but I couldn't tell ya how much those cost... :/

I didn't really want to buy new ones if I didn't have to since I won't have cats, they won't be doing much anymore.

well good luck either way, and you might want to have bill write a tune before you remove the 2nd set or the truck might not run right... just a thought... :)

If they're that badly rusted in...... bite the bullet and buy NEW ones......anytime you do exhaust work be prepared for extra cost.......ticopowell is also correct that Bill can turn off the rear ones but you still need the fronts!

O2 sensor do have a scheduled change out interval based on mileage.....

I finally got the 2 front ones out and put them back on. I left the 2 back ones off though since I couldn't get them out even after letting them have PB Blaster soak in over the course of a week. Ended up just plugging the holes for those on my new resonators. Seems to be running just fine though.

I still think you need a tune in order for your truck to perform properly. I don't know what would go wrong, but there could be quite a bit that is affected by not having the rear o2's when the computer thinks that they are there. is the truck throwing any codes?