Was looking to run straight pipe off the first cat (keeping the factory y connection), and just noticed the O2 sensor where i had planned on chopping. I am assuming that is an O2 sensor right? If so, how would be the best way of attaching it to the new straight pipe? Don't want to throw my EFI into wack.

 

Year? How you can do it depends on that.

 

Sorry, 1987 E-150, 4.9l w/C6

 

On that one I would just cut it either right before or right after the rear catalyst. That's the first area where you can find round pipe to weld to. It also makes bending the pipe much easier. By the time you bend a pipe to go from the Y over the crossmember it will look just as crumpled up as the stock one.

 

Well it's been cut right above the tranny crossmember, so the next piece of good round pipe it right next to the first cat and would remove the second O2 sensor.

Thought about just getting the Walker downpipe and starting from scratch.

 

2 O2 sensors on an 87???? Something ain't right....

 

Well i will study Chilton's, haven't really references that yet, but there are very much so two sensors on the exhaust. One before the first cat, and one after the second cat right before the tranny crossmember.

Maybe one isn't an O2 sensor. Not very exhaust savvy, what other sensors do they put on the exhasut system?

 

None back then.

 

An Exhaust shop can weld a new O2 bung in the pipe and install and sensor!

 

Hmm, Checked Chilton's and you're right (never thought you weren't) in that they don't mention anything else on there... So what the hell is it? guess this weekend i'll crawl under there and unscrew it to see what it is.

 

Think the connector between the two converters is the one for the EGR system. The 87-88 models I've seen had just one O2 sensor and it connects in the little balance tube welded between the two downpipes. I have an '88 factory Y-pipe on my van, and had to cap both holes.

My Y also came from the scrapyard cut behind the front converter above the crossmember. To connect the pipe back to the muffler I wound up taking a 2.25" to 2.5" exhaust adapter and having a muffler shop expand the 2.5" end up to a roughly 3" cone to fit over the end of the stock pipe [which isn't perfectly round]. Tack welded the adapter in place and bent it's rim down to better match the profile of the stock pipe, then welded it closed.

 

if ur good at welding just make a bung and weld it onto the pipe and stick the o2 sensor in

 

my 84 has a 02 sensor where the manifold connects to the pipe