Tom454

What was the stock exhaust system configuration on a run of the mill 87 ?

I have the front Y-pipe with 2 cats, u-bolted to a rear cat, 2 bolt flanged to the rear y-pipe, welded to the mufflers, with welded on black rectangular tips. Is this stock?

I have to replace the entire thing and would like it to remain as is.

c4cruiser

With the exception of the muffler tips, that sounds right. The OEM mufflers had a pair of round tips that were probably aluminumized steel. Not sure if they were stainless.

The pipe from the rear of the main cat to the rear Y-pipe was, IIRC, a 3" diameter.

vader86

Other than the tips, its right.

Joe C

get a stock replacement walker system. with the current cat technology, pre-cats are pretty much not needed. with the walker system's front y-pipe (pn 40449), you just need the main cat (pn 15749). you need that along with a new rear y-pipe, and new mufflers. for the mufflers I used walker's quiet-flow3 mufflers. these mufflers have dual functioning tips. overall, a bit louder than stock, but not in your face loud. I upgraded my 85 with the 86+ system, and no issues with fit and finish. I got the complete system from summit racing for around $550 shipped.

http://www.walkerexhaust.com/catalog...catalog-lookup

overall, a good sound, that rivals my 90's corsa system.

Tom454

I was looking at that setup on Walkers web site. Does the 15749 have the O2 bung?

c4cruiser

The 1987 has just one O2 sensor and for an OEM system, it's located on the driver's side of the front Y-pipe just below where it attaches to the exhaust manifold and before the pre-cat. There is no sensor on the main cat, just the tube for the AIR pipe that comes down from the passenger side of the engine.

If you go with the Walker system, you may want to check if there is an O2 bung already welded into the front Y-pipe. But any muffler shop can weld one in for just a few bucks. The bung itself should not cost more than $5-$6.

Tom454

Yes... that's the question I asked... does it have the bung already installed.

Joe C

if you're referring to the front y-pipe, yes it does - left side, near the manifold flange - stock location. BTW, might as well throw in a new O2 sensor. I typically use bosch. another tip - I've been using band clamps vs, u-bolts - a few dollars more, but well worth the cost. one final thing. walker has a smog pump air tube hook-up kit. basically a piece of hi-temp reinforced silicone hose and a couple clamps. I've used several of these - quick and easy hook up!

Tom454

Just installed a new O2 sensor. Has maybe 3 minutes on it.
RE: The tube... I'll look at the old setup to see if I can re-use it.
Otherwise, I'll buy the kit.