I've been trying figure out whether to leave the cat on my '87 4runner, or take it off. I've heard on several accounts that the 22re engine performs best with some back pressure, and taking the cat out eliminates some of that back pressure.
I've also heard that the general rule of thumb with any 4 stroke engine is to remove any restrictions from the exhaust system, so as to get the air into, and out of the engine as efficiently as possible. But all engines are different, I don't want make decisions based on the general rule of thumb, I want experienced opinion specific to the 22re.
my 22re has the emissions stuff removed, I live in Montana, so I'm not worried about emissions laws. I just want my 22re to run good, I don't care about the sound. What's my best option?

 

run 2.5" exhaust pipe with a glass pack or Flowmaster 40 ..
NO CAT
maybe throw in a new bump stick also...

 

Haven't considered a new camshaft yet. What else would I need with a performance cam? I don't want to go throwing performance parts in there and break something. Part of the reason the 22r is so reliable is it doesn't make enough power to break anything lol. But I'd definitely like to have a little more power. Is upgrading the cam as simple as removing the old one and installing a new one? Would I need a tune? I know these 80s ECUs aren't particularly tuner-friendly. I'd imagine I'd least need to upgrade fuel injectors to keep up with a bigger cam.
disclaimer: Im still pretty to new to the Toyota scene, still learning

 

The ideal time to change the cam is when you are changing the head gasket. There’s no way to get the cam out without loosening the headbolts, which in my experience results in headgasket failure anyhow. You’d want to use whatever rockers the cam mfr suggests.

 

IT might be helpful to give the techs at LC ENGINEERING a call and give them your goals and budget... they're great to help you!

 

http://www.4x4wire.com/toyota/tech/camshaft/

 

My wife had an 86 4Runner with a 22RE and I can tell you how it ran without the cat on the stock engine. She drove such a short distance to work that it never really got hot long enough to get rid of condensation that collected in the pipes. One day she said the exhaust made a weird noise and now it sounds like an airplane. The guts of the cat fell apart and blew out the tail pipe in pieces. It definitely got loud, sounded like crap and it felt like it lost low end power. It felt a little better on the freeway.

Then the rest of the exhaust rotted out and back then Downey was advertising this great performance upgraded exhaust system. At the time I think it was cheaper than OEM. I don't remember but, I bought it. I think it was 2 1/2" and included a cat. Sounded much better with a cat but the larger tube killed the low end. Hated it. This was a completely stock truck otherwise.

So.....my experience anyway, is that you might be ok without the cat. It will be louder. I don't recommend too large tube diameter though if your engine is stock.

Now my 88 pickup had a ported head, larger valves, performance cam, header and 2 1/4" exhaust with a cat. Passed emissions and ran great. No computer mods and stock injectors. Gears to match my tires.

Just my personal experience.

 

I have a Magnaflow converter that is essentially a hollow chamber (federal) I had a legitimate magnaflow Calif converter but it blew out after 6 months. The sound level is ok. not an issue. My smog tests go fine.
I'd love to buy an oem bolt on cat if anyone ever decides to sell. They're not worth much at the recyclers.