Yeah, I dunno about the cat creating enough backpressure thing.
It makes sense back pressure would go down due to the fact that half of the exhaust piping has been increased in diameter, regardless of the cat.

I'm not an expert, but that's just my 2 cents. What is the stock diameter? I'm too lazy to measure it. LMAO. But seriously I am. lol.

I think just replacing the stock pipe back from the cat with the same size piping to a flowmaster or magnaflow muffler might be pretty good. I think I'd like that.

 

I am in the process of installing a catback in my girlfriends 4runner. I got the new muffler on but the replacment tailpipe does not match. So It has been dumping right out into the rear axle (about 7" away)... It also vibrates the whole truck haha!

Need to figure something out.....

 

if you have stock exhaust pipedont get a flowmaster. make sure you get a little bigger like stated above. i got a flowmaster 40 and i hate it. the only way people kno i have it is if i tell them. its sounds kinda ricer like at lower rpms and then you cant here it after you hit 3rd gear. im gonna run a magnaflow highflow cat with 2 or 2.25inch back to a glass pack. ive heard they rumble pretty good

 

http://store.summitracing.com/partde...5&autoview=sku

I just ordered it, it'll get installed this Sat; I'll let you know how it works out

 

I got a 50 series 3 chamber muffler on mine and it sounds really nice. Very deep rumble. not much louder than stock at all. at times it is actually quieter than stock because the tone is lower. I know i have a v-6 but it still would probably have similar effects on a four banger.

 

not sure of the stock diameter, believe it's 1 3/4 or 1 7/8.
I put 2" on both my 22re's, from my cat back through the mufflers (cheap turbo muffler on the 91, magnaflow on the 88, don't recall the model- muffler shop had it on the shelf from a customer cancellation) and 2" out behind the wheel. Both picked up a little torque.
The 88 needed it after going from the stock 28"s to the 31" that are on it now and was almost as strong as it was before the tire change. Then the 88 had it's cat stolen so put a magnaflow cat on- 2" in/out to match the pipe and picked up a little more torque. Unfortunately it still doesn't hold hills as well as before the tire change but it's as quick as it was before.
The 91 just had it's cat replaced with a magnaflow one, 2" in/out and it seems to be a tad perkier- impressive considering it's an automatic.

 

The stock diameter is 1 3/4 for the V6.

Looking forward to iamsuperbleeder's install!

I just got an engine with performance cams, intake and header, and will be getting the crossover from Downey soon, and then off to the exhaust shop. I plan on no cat, and 2.25" piping, but maybe 2.5" since I have the performance cams.

Will post my result, along with a sound clip and video.