Exhaust Woes

[alastor11]

Okay, I got my 02 sensors so I can get rid of the pesky P0141 code (thought I would do both even though only the one before the muffler is sending the code). Well, I crawl under there and notice the age and rust and booty-fabness going on (the cats are welded together, probably to stop a leak, bracket is welded to the pipe because ist rusted off, etc.) and worse of all, there is no way I am going to wrench the nuts off of the studs on the 02 sensor. One nut on the rear sensor has already rusted away, the other has rusted to a round blob. I was afraid to look at the front sensor.

Choices: I did some searching in the forum and my options seem to be 1) pay $2000+ to replace the whole system using OEM parts; 2) buy some after market cats (front and rear) and cat back parts (need the 02 sensor flanges) and do it all myself, or 3) take it to a muffler shop and see what can be fabbed up to my liking.


Questions: Can the down pipes from the manifold only be purchased with the front cat? If I take it to a muffler shop, can they fabricate down pipes and all the necessary flanges for 02 sensors? What have others done in the salty areas of the Mid-Atlantic region?

Thanks for any input.

 

[OGBeno]

Questions: Can the down pipes from the manifold only be purchased with the front cat? If I take it to a muffler shop, can they fabricate down pipes and all the necessary flanges for 02 sensors? What have others done in the salty areas of the Mid-Atlantic region?

Thanks for any input.

Yes, front cat is a part of the front pipe/Y-pipe assy. IIRC, $1200.

I'd go with custom bending, universal cat (1 or 2) from the manifolds back.

Go with stainless. Will cost more, but it will last for eternity (unless you wheel the crap out of it.)

 

[drsales]

Check out the after market cats. Purchased the 2 cats and y pipe for $600+

 

[smokethedog]

I had the same issue with my front 02 sensor, just a blob of rust where the nuts should be. I thougth there was no way I was going to get them off without breaking a stud in the process. I crossed my fingers and coated them with pb blaster every day over a period of about a week and was able to get them off using some pliers. The nuts were rusted beyond the point of putting a wrench on. I was really suprised. PB Blaster made a beliver out of me.

After I got the O2 sensor off, the next issue was the old o2 sensor gasket, rusted blob as well. I used some pliers and pried and pulled what I could get off in peices, then used a metal file (filed like crazy) to get the rest off. I eventually got it all off and installed the new O2 sensor. I put new nuts on, I think they were 13mm, but you should double check that. I think I saw another post that had the actual nut size and thread needed, do a search and you should find it). I had enough of one of the old nuts to take to hw store and find the right size.

After installing everything back, Initially I had a leak, which required removing the O2 sensor again and more filing, and another new gasket (it was cheap), but that fixed it. All sealed up now.

hth and good luck,
smoke

 

[e9999]

before buying aftermarket cats, check to be sure -if you don't know already- that those are OK by your state emissions board if there is such a thing where you live...

 

[fadetogray]

I've got alot to say about this b/c I'm still hot about it. Problem same as yours, but I chose the cat route first b/c I read and watched the sensor voltage changes and thought they were ok. Went to Bubba's muffler shop. He replaced both cats and muffler for $500. Got rid of code, BUT THE DAMN THING SOUNDS LIKE A SWARM OF ANGRY BUMBLE BEES! I got 1 block down the street, turned around and went back. He tried one big cat instead of two smaller---that was worse. He said that's as quiet as aftermarket comes. I then realized that 'quiet' was quite an open-ended term. I went to several other shops from name-brand shops like 'meineke' to 'midas' to other custom exhaust shops. I thought the world of mufflers cannot possibly be that complicated---well it is. I realized I needed to start asking the right question. When I went in to a shop I would simply point to my LC and say 'I want that to be quiet as a cadillac.' to which they would reply, 'we can't guarentee that.' No matter where I went I was told aftermarket exhaust is not as quiet as OEM. I went online--good luck finding OEM for Mr. Ordianry Sucker even from Walker, who manufactured the OEM mufflers for Toyota LC from early 90's to '95. I suspect they did as well for the '96, but just don't list it. So I said screw em' all, I'll go to a junk yard and get whatever the hell I want. Wrong again! ALL yards (including yards I called across the country) would not sell me a used cat---apparently special interests screwed us in advance back in the 90's when the EPA was drafting all the rules/regs. It's illegal to sell used cats. It keeps cat manufacturers in the money and whoever they paid for the law. Now for what it's worth, there is an outfit online called 'smith bros.cat' that remanufactures stock cats for about 1/3 new OEM price. (I bought one for a Honda Odyssey, it was OEM reman and works fine). As far as used muffler from junk yards, most were very reluctant or just unwilling to even consider it. I disgust and anger at the amount of time I had sunk into this wild goose chase, I gave up until I thought of a better plan. I'm still out $500 with my bumble bees. I suppose if I took action at this point I would get two remans and two walker mufflers from shops/online who sell walker. You can go to walker's site and get part #'s. The reason I would get 2 is for dual exhaust. It will cost a fortune anyway, why not have a good exhaust shop weld/bend duals? There's room for the parts under passenger side if the shop can bend proficently, I'm just not up for more expense since I can still feel (and hear) my last screwing. I'm getting a tension headache even going back through all this work I did just to get passed aroung for more screwing

 

[alastor11]

Thanks for the input and sharing of your own experiences.

We have emissions testing here every two years. They are not too psycho, as I replaced the cat on my mini truck without any hassle. Getting an de-smogged V8 in the FJ40 was a totally different odyssey though.

I might try the PB Blaster route and see if I can find the replacement nuts. I still worry about how much longer the exhaust system is going to last before another leak/break occurs. That is why I am figuring on just replacing the whole system and feeling the pain all at once.

I really do not want my 80 to sound like a can of bees, so I might look into the dual exhaust idea. I am currently searching for a shop that has some creativity, unlike the Midas I went to for another issue, as all they could do was cut and weld, and not even do that very well.

My biggest issue is that I have to get the beast through inspection so I can title the thing. Still running around on 60 day temp. tags.

 

[fadetogray]

Here in Nashville Tennessee if a vehicle is 1996 or newer, the ANNUAL smog inspection only consists of reading any emissions related codes in the vehicle's OBD II computer. No codes means you pass. If older than 1996, they actually sample the exhaust, use a mirror to inspect for the exsistance of a converter, and leak check the gas cap. When I bought my '96 LC, it had the 402 code for catylist so I knew, as you, it had to read ready w/o codes for me to tag it. Now the bubba exhaust shop put in a generic OBD II converter and the computer liked it just fine. The problem I had then was with the noise, which I believe is due to cheap aftermarket muffler/cat, not simply non-OEM as some shops tried to tell me. If I wanted a specific exhaust note, then I could accept the 'non-OEM is the problem' explanation. But quiet should be acheivable w/o rocket science. I would go with Walker b/c they made OEM up to 1995 or find a sensable junk yard that will sell you mufflers off of a LC or even a GM truck, cadillac, etc. that we know are quiet. The reason I recommended duals is just for additional power. Since stock design is for 2 converters and 1 muffler, all you would be adding is one more muffler and piping. Now what I assume is that leaving the O2 sensors on one side of a dual system and no sensors on the other side would not effect the computer's engine management. I have not tried this so it is only an assumption. For what it's worth, I have an old 1986 E350 van I use for hauling junk, yard work, etc. It's real rough with rebuilt motor/trans, carburated, and leaking valve either intake or exhaust or both, but the point is it bombed the smog inspection even with a new cat. So I used rubbing alcohol. That's right, in the tank. 4 gallons of rubbing alcohol in a near empty tank got me from home to the inspection station, where I passed with flying colors, and to the nearest gas station to fill up with unleaded gas. If rubbing alcohol, which is 10% water, makes you uncomfortable, find a place that sells alcohol fuel for racers. There are several local tracks around here where I could have bought it, but I was to lazy to make the drive when Wal-Mart was 60 seconds away. If you were to try this with your cruiser however, you would have to run it for a couple of days on alcohol AFTER the computer was reset so the OBD II computer will finish it's 'readiness tests'. Just b/c there is no light on the dash does not mean it will pass inspection. The OBD II computer internally reads 'not ready' until it samples exhaust readings under various conditions over a couple of days including hwy driving, acceleration, low speed driving, and idle. Only after it completes its 'readiness tests' AND show no emissions related code will it pass an inspection where they read the computer. Good luck.

 

[alastor11]

Exhaust Woes Update

I took the beast to a local shop and explained the problems and what options I was looking for. The guy told me that because there were some 90 degree bends in multiple places and it was hard up over the frame by the axle, it would be difficult to do stainless 2.5" much less 3" pipe. He did say he cold fab the down pipes into the Y pipe and go from there.

I opted for the middle road on this one and had him cut the cats out starting just behind the front 02 sensor and just before the down stream 02 sensor. Both cats were pretty rusty and the mounting flanges were leaking and had been welded together. He was able to fit 2 OBDII universal cats in between and save the flange mount studs for the sensors so new ones could be installed. Only slam was that after it was all done there was a noticible leak at the rear seam of the muffler where it had not visibly separated (only noticed it when they started it up and the white smoke due to the the welds puffed out). Not a very loud leak though. So now I am going to be shopping for a new muffler. Still runs quietly and does not sound like a box of bees.

Best part is that I have not gotten a P0141 code, and since I messed with the EGR vacuum hoses and took apart the modulator I have not seen the P0401 either. I am keeping my fingers crossed.