Just installed - M&K 1 in 1 out

[Kidasters]

Hey Guys -

A few months ago, I bought a 1 in 1 out Dynomax muffler from another Pelican, to change from the stock muffler.

After looking at the condition of the nuts/bolts on the muffler/cat flange, I decided that I would try to hit them with penetrating oil (liquid wrench and kroil) every day for two weeks. And - that didn't work.

Knowing this was going to be a pain if I had to grind the bolt heads off, I waited. And waited.

Finally got the motivation to do it. Got out my dremel and ground all 3 bolt heads off. It was painful. It took 1/2 a day. But - ground off and punched out the remnants. Except the one that is at about 8 o'clock. I had to punch it most of the way through, and then cut the bolt in half again - since it wouldn't clear the cat.

I also struggled with the stock muffler straps. the passenger side one got all twisted up, because the bolt was so corroded. But, I got them both off and pulled the stock muffler out.

Went to mount the Dynomax - and it doesn't fit with the stock heat shielding in place. I guess it might fit if I took that out as well, but I decided I didn't want to. So, if anyone wants a used Dynomax one in one out - pm me.

Decided that I wanted to do something that would fit in the stock location without modification. So, I went with the M&K one in one out.

One thing to note - when I ordered the hardware initially, I ordered two new straps (driver's and passenger side - becasue P-side is larger), new allen head bolts for the straps, Lubro Moly copper thread compound, and a new gasket. When I ordered the M&K, I also ordered a few 40 mm long 8 mm 18-8 stainless allen head bolts, and some smaller 18-8 bolts (6 mm) to re attach the shield for the cat. I also had to order a new rear mount for the heat shield, because I damaged the one on the car when I was grinding bolt heads, and the clamp bolts that go on that.

The nice thing about M&K is that they send you all the mounting hardware too. Muffler showed up, and it had bolts, clamps, gasket. Very nice.

One more thing - I had a bunch of copper nuts left over from when I did the exhaust manifold on another car. The nice thing about them, they are a "special clearance" nut - they take a 12 mm wrench instead of a 13 mm. Which is nice when they are on an exhaust manifold. Maybe irrelevant here - but still nice.

So - I went to install the M&K. I noticed that the cat flange seems to have a small ridge on it. I didn't think it would be a big deal. Put the gasket on there, and started bolting things up. The straps are a bit tricky, but I got them on. Yep - plenty of anti-sieze on the bolts that attach the muffler to the cat. Once done, as tight as I could get it, I started the car. And - I'm leaking at the flange. The gasket was so loose that I could wiggle it.

Damn.

What to do? Take it all off and grind the end of the cat? But wait - I have the other gasket that I bought. Unbolted the muffler and loosened the straps. Slipped the 2nd gasket in there and put it all back together. Tightened it down, and it's great!

I like the sound of the M&K. A little deeper sound than the stock muffler, but not droning when driving around. Plus - it's at least 10 lbs lighter. Overall - very happy.

[gamin]

I have the M&K 1/1 muffler along with the M&K pre muffler. Great sound and saved a few pounds. High quality stuff too.

[Kidasters]

I thought about doing the pre-muffler too, but that's more bolts I'm probably going to have to fight, as well as a new 02 sensor. I'll put that off until later I think.

[gamin]

Nuts and bolts are cheap. You use the same O2 sensor with the M&k that is on the car now. And yes you're right, exhaust bolts can be a pita.

[TheSt|G]

Nuts and bolts are cheap. You use the same O2 sensor with the M&k that is on the car now. And yes you're right, exhaust bolts can be a pita.

Probably time to change the O2 sensor though given the mileage.

[Sox Fan]

I put the M&K 1/1 and pre-muffler on my 89.

It was a full day to remove the old exhaust. I used a grinder, Dremel, torch, drill, Sawzall and every other instrument of torture I owned.

Complete PITA but completely worth it.

[Kidasters]

Thanks guys -

I figure I'll need to install a new O2 sensor when I do a bypass pipe, because I bet I can't get the current one out of the cat.

Drove around yesterday and love it more. The only bad part was that I left my brand new gas cap on top of the pump at the gas station, and when I went by this morning (with some hope) it was gone.

Rats.