Today, my old man and myself decided to tackle the oxygen sensor one more time. This time, we removed the front passenger side wheel, and some little flaps that separate the engine compartment from the outside world.

There it was, in all its glory - manifold oxygen sensor. Tried using the torch, wouldn’t budge. Tried PB blaster, wouldn’t budge. Tried hitting it with a freshly sharpened metal chisel, nope. So, it was time to remove the manifold.

Step 1, remove 4 bolts which hold the heat shield in place. Easy enough. I needed lot of extensions for my socket set, but it was easy.

Step 2, remove the 8 nuts holding the manifold. 4 top ones, easy peasy. 2 bottom ones, fairly easy. Third bottom one, hard but not impossible. 4th one, no go. No fucking way of getting to it because the engine mount is in the way. I could get the socket over the nut, but then I couldn’t connect the angle piece as there was no room. Every video I watched said you have to remove the mount for drivers side only. I guess they all lied or they had some magic tools I didn’t.

Step 3 - remove engine mount. Put another jack under the engine - not easy to find a spot that you can use - and make sure the engine rests on it. Remove 4 bolts which hold the mount. Pull on the mount and that gives you enough clearance to get to the last manifold nut. This was probably the easiest part of the whole job  


Step 4 - remove the three nuts connecting the manifold to the exhaust flange. No go - seized, completely. Dremel tool to the rescue - chop them off. Super pain in the butt - no room down there. Finally got them chopped off, then pried the pieces apart as they were caked together.

Step 5 - fix the used manifold I got from a guy which removed his for TRD supercharger installation (so jelly). I had to retread the flange bolts as they were messed up - I had a set of new ones, but surprise surprise, completely seized. Thankfully I had the 10x1.25 tool handy to do so.


Step 6 - install the new ogygen sensor, install the manifold, connect everything, make sure I have no leftover bolts or nuts.

Step 7 - turn the truck on. Everything works. Nothing buzzes. It drives well. Check engine light - STILL ON!!! Faaakkkk.


We replaced the air filter as well, added a bottle of CRC “guaranteed to pass emissions” - not sure what else to do. Anyone with a failed emissions test? What did you to your car to make it pass? Check engine light is not an issue - it’s jusy an advisory fail, but the CO2 was 4x the allowed and HC was 1.37 (allowed 1.2). Should I preemptively replace the MAP sensor ($90-180) or just clean it? Any other sensor to replace or look into? Replace the cats? Truck has 132k miles and it’s 18 years old. It’s running like a well oiled machine other than this  

This is why I drive new cars...7 hours of work, chunk of skin missing, and still not sure if I’ll pass emissions.