Exhaust manifold to y-pipe and o2 sensor help
 

I have this '96 Bravada I bought with y-pipe to muffler gone and I need to know if there are springs that hold the y-pipe onto the exhaust manilfolds. Making if kind of flex rather than bolt it tight together. And if so, what do I torque it to? Haynes manual dont cover this part.
Second, I read in other posts that '98 and newer trucks have 3 o2 sensors. Anybody know if the '96 Bravada has 3 sensors? I can only find 3 pigtail plugs to plug o2 sensors in. But the y-pipe I bought from a dealership has 3 bungs in it not counting the sensor for the cat. Thanks for the help. Eric

RE: Exhaust manifold to y-pipe and o2 sensor help
 

They have springs on them and you can buy them with new studs at Napa. You will need to tighten them to 18-22 foot pounds. I don't know about the O2 sensors, but you may find another O2 plug on the passenger side of the trans, if thats not one of the connections you already have.

Just a little info for you, I just changed the y-pipe and cracked manifolds on mine, once you tighten the flange to manifold bolts and if you still have a exhaust leak, check and see if any of those springs are compressed all the way down. If you do have some that are compressed, the flange on the y-pipe is hitting that little collar on the stud. Best way to avoid this is to attach the y-pipe without the cat attached and to evenly tighten the nuts. I made three tries at this before I figured out what was happening. I kept trying different flange gaskets because I thought they were giving me the wrong ones. Also, I had to install a used y-pipe, so that may have been some of the problem. your lucky they still carry the one for yours.

RE: Exhaust manifold to y-pipe and o2 sensor help
 

Great! Thanks for the advice. Unfortunately, I don't have the cat right now to getin the way. I am putting on one part at a time while money allows. As far as the y-pipe, I searched all overfor this thing before going to the local dealership only to be told they don't have one either but he checked the database only to find one in Minnesota. I told them of the GM Parts Direct price and they matched it. I did buy the spring, stud, and nut kit's from local store but just wanted to make sure i was doing this correct. Thanks again for the heads up and I will look tomorrow for that other plug. Eric

RE: Exhaust manifold to y-pipe and o2 sensor help
 

To answer the O2 sensor question, there are four O2 sensors on the 96-97 trucks. Two upstream, one in each primary down pipe before the "Y" in the y-pipe, one directly after the "Y" in the y-pipe, then one after the cat.

RE: Exhaust manifold to y-pipe and o2 sensor help
 

I was afraid you would say that. I guess while I'm under there putting the y-pipe on, I will have to scour the underside for the hiding 4th connector. Thanks, Eric

RE: Exhaust manifold to y-pipe and o2 sensor help
 

Ok, I found the last o2 sensor connector while I had the truck up on the ramps and had better light. Bad part is I now have to go get another sensor. Thanks for the help. Eric