Topic: 22R tuning.

[MarkyB]

OK, first the facts.
1984 4Runner, 22R Carbed, stock. Stock exhaust system, complete.
It runs pretty good, but I have a pretty strong exhaust smell.
Can I tune that out?

[jimbo74]

what kind of mileage are you seeing out of it?

can you define strong exhuast smell?

[BLACKDOG]

Chances are you've got an exhaust leak, not a tuning problem.  Where is the smell the strongest?  look along your exhaust system, do you see any areas where it looks as though it gets abnormaly hot, or are there any sooty areas?  especially around connection points. 

[MarkyB [OP]]

I don't smell it in the truck unless the rear window is down.  Standing anywhere around it you can smell it. 
Long story to describe smell:  I used to have a Mustang GT.  I installed  a prochamber on it.  With the cats removed it had a strong hydrocarbon smell.  THat is the same smell I got now.

I have not seen any signs of a leak, but I will double check.

Oh yeah, mileage about 16mpg.

[jimbo74]

its a 4runner, you arent supposed to be driving with the rear window down, in fact, i think it actually warns not to do that, because it will suck in exhuast fumes

[BLACKDOG]

its a 4runner, you arent supposed to be driving with the rear window down, in fact, i think it actually warns not to do that, because it will suck in exhuast fumes

  if you want to drive with the rear window down, you also need to crack other windows in the vehicle, so you have airflow that keeps the exhaust from entering the vehicle.  When driving, you've got airflow currents on all 4 sides fo the vehicle (top, bottom, left, right)  creating a dead spot behind the vehicle.  The exhaust kind of "sits" in this area.  With the back window down, it enters the vehicle. 

[MarkyB [OP]]

OK, I don't normally ride with the rear window down.
I was making the point that there was not an exhaust leak.

The exhaust smell should not "knock you down" when you walk up to it when it's just idling.

[BLACKDOG]

OK, I don't normally ride with the rear window down.
I was making the point that there was not an exhaust leak.

The exhaust smell should not "knock you down" when you walk up to it when it's just idling.

No it shouldn't.  If you don't have any exhaust leaks, I'm not sure what to tell ya.  I'd guess that you're running rich, so you may want to just lean it out a tad, or you could be off a bit on the timing, and your exhaust valves are opening before the combustion process is completely finished

[79coyotefrg]

sounds like the cat might be  plugged up. 


kinda  smells like a rotten egg  dont it

[kneedownnate]

That's what I was leanin toward too, bad kitty.

[Wermz84]

When my truck had a noxious smell it turned out the Cat was completely burnt out.  and a couple of little leaks around it.

[MarkyB [OP]]

I talked to my buddy that I bought it from and he said the motor has been rebuilt and he put all new ignition parts on it.  Therefore it has to be the cat.  That means I'll have to replace it.

I'll just have to put some headers and a Flowmaster on it so that it all matches.  It has to match ya know.

[Wermz84]

You know it does.. 

[kneedownnate]

Before you go trying to unbolt the cat and get yourself all good and hot, put some heat to the nuts right before you try taking them loose.  Don't do too much cause it'll heat the stud too, but if you can get just the nut a little hot it'll pop off a little easier.  You should try just punching out the cat first, just to see if it gets better.  If you go with a new one you can get a monolithic free flowing cat from magnaflow for pretty cheap.

[MarkyB [OP]]

There is a mom and pop (literally) muffler shop in Lucedale that I'll take it to for the work.
They are very reasonable on prices.  Everything past the manifold is welded anyway.