rustyrunnerboy

Hey all,
I just picked up a exhaust system from manifold out (excluding manifold). My current downtube has a huge crack in it and I'm loosing brain cells riding around breathing exhaust (not to mention that the girls complain). It's all pretty basic stuff: your stock 1 3/4 inch tube, universal cat etc etc. I was reading on another post that this guys snapped off the bolt (or whatever the technical term is for it) that attaches the downtube to the manifold. I don't particularly want to follow this example so is there anything I need to do to avoid this happening, should I take it into a shop and get them to remove it?

Secondly I don't want rust to start eating through my muffler etc in a couple years so is there some sort of spray on, high temperature rust inhibitor that I could use?

Finally a question about the o2 sensor: it's currently placed just before the cat (I guess the previous owner cut a hole and put it there) so for now the original hole is just stuffed with another one that I bought. I'd like the attach the one I bought but it seems the wires coming out of the 'functional' one right now aren't the same as the other one I bought, they are much thicker. There is nowhere on the wiring harness in the engine bay to attach the new o2 sensor. Any ideas?

Also a few instructions on installation of the new system would be great. I'm pretty mechanically inclined and would figure it out in the end, but if there is anything major I should watch out for. I'm installing new hangers to hold the system in place aswell since the old ones broke.

1989 4runner, 22re, bone stock.
Thanks in advance,
Drew

dcg9381

I'm sure someone has a "used" downpipe they'd sell for cheap.. I think I tossed mine in the trash a few weeks ago.

I like to use stainless bolts and a lot of anti-sieze when working on the exhaust. Just get the old bolt out and re-tap. Use stainless.. It takes a lot longer to get crapped up.

On your 02, the connector is under the seat. You'll have to post a photo of your "new" 02 sensor. Wire gauge isn't that important, but wire function is. The 22RE has a heated 02 sensor and you need to get the wires right. Most aftermarket sensors come in flavors from 1 to 4 wires. Splice in the connector from the old 02 after you correctly figure out the function of the existing wires. More info is needed!

If you're in a rust prone area, you can go to "aluminized" exhaust, stainless, or just try and keep the salt off those parts. Other than ceramic, there isn't a good coating that I know of.

rustyrunnerboy

thanks for that info...my new o2 sensor has only 1 wire going to the little round plastic connector, will this fit somewhere along the line of where the current o2 sensor path to the ECU or will i have to do some splicing as you mentioned even if the current o2 sensor has more than 1 wire?

Also does anyone know the best way to remove the nuts on the manifold without snapping the bolts?
Drew

dcg9381

Drew, if you've got a one wire sensor, you need to figure out which wire is the ECU 02 gauge.. there may be two, one is for the 02 value, one is a ground for 02 heat.. .You want the 02 value.

Note a heated sensor is better, especially that far from the manifold.


Best way to get them exhaust bolts off is to soak them in some penetrating oil several times over 24-48 hours... And then cross your fingers...

toyota_mdt_tech

Squirt the studs and nuts with a light penetrating oil, ie WD40, PB blaster, Toyotas own high performance penetrating lube etc. Now get a real good 14mm 6 point deep socket, impact, no chrome. Crack it loose and see if it unscrews easiliy. If it doesnt, massage it back and forth until it does. ANd replace the nuts wi th new OE units, dont get aftermarket nuts, they will come out later and require a 17mm socket which usually doesnt fit int he tight area.

rustyrunnerboy

cool, thanks for the info, will try all of that and if I don't come back to this thread then I haven't cracked a bolt and have found the right place for the sensor. fingers crossed!
Drew

rustyrunnerboy

ok, i'm back, but i haven't broken anything...instead i'm trying to figure something else out...I got a 1 wire o2 sensor from a guy i got some parts from as a freebie. i've got a 4 wire sensor in the truck now and i'd like to try use that other one i have because i'm pretty sure that my current one isn't very good. i know that dcg9381 said that i need to find that wire for the o2 value going to the ecu. question is: how do i find the right wire, and will not using the other 3 wires make anything go awry? the o2 sensor is up on the manifold so i shouldn't have to worry about heat eh?
thanks in advance,
Drew

drew303

Id look into a header

I put a all new exhaust on my rig after i bought it. I bought it with a cut head pipe (dumped under the cab before the cat) ... it was a mess and louder than hell.

So I had a shop order a new head pipe ($200, yea no lube either when i walked in backwards)... Then I had to buy a new exhaust manifold. In the end i was out $550 for a stock exhaust, well i have a magnaflow on it.

Then i went through hell getting the "new" head pipe to seal to the "new" exhaust manifold, broke a stud in it.. Iron manifolds SUCK! and i have the aftermarket 17mm nuts, its a pain in the ass but even with only two bolts holding the head to the manifold it doesnt leak anymore.

Proper gaskets are important, home-made or thin paper ones DONT work. You need the three-layer cement type.

Anyways, I could of actually saved a $200 if I had gone with a header. (they're like $150-200 on the net).

I think engblder sells them to

rustyrunnerboy

yeah, i want to get a header, that's a future project though, and i do like the LCE ones i think, since they specialise in toyotas, engine builder would also be another option, but when i buy it, money won't be an object (to a certain extent anyway). what i'm wondering is what i need to do in order to hook up a 1 wire o2 sensor to a 4 wire o2 sensor system already in the truck...
thanks,
drew