heres the cat, and the flanges. bolts directly in with 14mm bolts.

 

did you have to weld those on the cat or did you buy the cat with those on?

 

Welded on. my exhaust is 100% custom.

 

ya i have the same cat you do i might just do what you did but i dream of having headers one day. lol

 

isnt there an easy way to test it? like take it to a local shop and have them hook a machine up to it or something? ive always wondered that about my rig too

 

Dyno. Dyno time is not cheap

 

haha yeah, but this cat isn't legal on my truck here in cali. So im gonna do some changing around a bit. dont worry. I'll update this as I go, but in quick words, Im gonna shorten my Y pipe... there is no reason for it to be almost 2-3 long. I also want to fit my stock cat on in its stock location. and cutting the Y pipe and moving the o2 sensor closer may cause the engine light to not come on.

Yeah, I could take it to a dyno. but why? lol its only a 4runner... If it really matters? i've raced a single cab v6 on the road just to do it as a test. I was ahead a few car lengths and found myself waiting for it to catch up, then I could just WOT and blow by it again. These headers are quite an upgrade for the 3vze... feels like a non restrictive motor now.


How much is a dyno, jay?

 

i would say dynos are expensive as , more than smogging a truck i bet.. call around. its gonna be different just about anywhere

 

yeah, But I wanna finish my truck, get it tuned back to factory and put an intake on it. then if im feeling up for it i'll take it to get dynoed... I mean, stock is 150, and with a restrictive exhaust. I had a talk with a guy at a gas station that was in a 2wd 3vze 4runner that thinks i might be at 175-180 hp... I just rolled my eyes, filled up my truck and went on with my day... lol

 

well i wouldnt be suprised if you got a pretty big increase. i mean is it definitely a noticeable increase since before you got everything on?

 

yeah... huge difference. in both sound, and power. when I get everything situated, intake, o2 sensor problems worked out, and 100% done. as in im not putting any more money into my exhaust. i'll do it.

 

IS your '92 only running the single primary read O2 versus the later double set, primary and secondary reads? (Ours has two.)

[Advise] IMHO just throw on the new Cal-legal Dynomax like NorCalBorn did.
http://www.youtube.com/watch?v=tJESSkGRzR4



What you're doing with the straight pipe isn't ilegal just for smog reasons. The muffler you have is just a baffled system and will not function properly as a spark arrestor like a cat-conv will. You're asking to start a fire when off roading, not to mention you should at the very least run a pair of resistor boxes to modify a signal back to the ECM so you don't throw codes or have an improper mixture in closed loop happening, again, possibly causing a spark, let alone burning the crap out of your valves. The FSM lists the specific resistance values for the system, then either verify using a voltometer and potentiometer, or just get the correct resistor and be done w/ it. *Adding a supertrapp mini tip will get you past the spark arrest clause.


[/Advise]

 

So Mak92-4RnR,

I guess you now have 3-4k miles on your truck since the header install. I have really enjoyed the entire thread, lots of great info here. I am curious about a couple of things though.

Are you having any problems with cooking the passenger floor, starter, brake lines fuel lines ect.? I remember you discussing sheilding the starter and misc. lines, did you ever follow up on that? If so, would you mind posting a couple of pics of that effort?

Also, now that it is done, if you had it to do over again, would you do anything differently?

Your write up has been really informative, thanks for going to all the trouble to document the process as there are still lots of folks who would like to do the same job when money and time permit.

WJ

 

I never followed through with wrapping anything. Starter is still brand new, brake lines and still silver in color, brakes look and feel fine. still feel full of compression ( no squishiness in the brakes from burning up brake fluid in the lines ) everything is 100% A-OK. I'll post some pictures of what everything looks like.

I think the only thing I would do differently is use the stock bolts. I dont like the way the new ones look that came with the headers... its less hassle to use the stock ones so you dont have to take the bolts out. plus it saves you from cross threading them into the manifold :O big fix if you mess that up.

I'm glad that this could be helpful I had no mechanical experience prior to this so im almost positive anyone could do it. the only problem i had was the crossover lol

Im not 100% done with the exhaust yet, more modifications to it are coming, since i have to pass smog in june. lol im gonna refit my stock cat in there, shorten the Y - pipe and also gonna give it a little "tuck" when i get my body lift installed.

 

Not to hijack or anything, but I have about 25k on my header install.

So far I have no problems either. Though I DID buy some heat shield tape from AutoZone, and covered the following.

-Top and some side of the starter
-Some wires
-The fuel lines (fell off about 10k ago)

I bent the brake lines slightly away and haven't had any issues.

I do many highway miles, through everything, heat and cold.

ONLY thing is over the summer on 10+ hour highway trips the pass floorboard gets pretty toasty, but not enough to do any damage.

 

I did bend the brake lines out of the way, but thats pretty much it. everything fine, I checked it constantly when I first got them on no problems!

 

Couple questions...

I've begun to notice that my exhaust rattles at 2.5k rpms, ONLY when I let off the gas. when I push the gas, it roars down the road, but then let off the gas, I get a tone, then when it hits 2.5k it rattles. But the noise appears to be coming from the inside of the pipe? I thought maybe its rattling on something... heres what I think it might be...

1) rattling on something close to the engine? its not touching ANYTHING... so I dont know what it could be?

2) Back pressure issue? it makes the noise around the crossover / Y pipe... but it sounds like its in the pipe?

Im thinking its number 2... there are NO leaks in this exhaust system. i've had it checked over and over again.

on a cold start my truck sounds like a pure straight up rice rocket... but when it heats up and expands, it sounds amazing but has the 2.5k rattle. if anyone wants any more info, i'll be glad to share.

anyone got any ideas?

 

my truck makes the same sound that yours make but i always thought it was just hitting something

 

Do you have headers too? I cant stand it any longer. I seriously have moved everything out of the way, took off all the heat shields, it still rattles... got any suggestions?

 

no i dont have headers. i have a magnaflow cat and 8" glasspack but it still does it tilll around 3000 rpms. but after that the crackling and popin from the glasspack takes over.lol