They would never get clogged enough again to cause a big enough blockage to cause performance issues.

 

Especially since it was gutted only a year ago.

 

I did change the o2 sensor before the last inspection. That made it run a little better but not much. It did do MUCH better on low speed NOX than the year before.

I have been reading threads on the AFM and adjusting it two-three clicks leaner. It seems to make these engines run a little better.

 

No donot ever adjs the AFM. EVER! I don't care what ppl on here say its not wise to do so. They are preset from the factory just perfect they require no adjustment. Now if you want to check the AFM to see if its operating properly. Get and haynes manual or what ever and do the OHM tests. If any of them test out of spec the AFM is considered bad and needs replacing. If it tests good do not mess with it and keep trouble shooting.

 

I was having identical issues with my 91 3.0 I changed the catalytic converter yesterday with a magniflow High Flow cat the truck has power once again it solved 90% of my problems. Although if I set the idle around 1100 rpms it runs as smooth as the day I bought it but if I turn the idle down to 800 rpms it runs like it has a miss and the truck shakes then if you turn the a/c on it feels like its going to die. My TPS tested at 980 ohms at closed throttle so I think that might be my remaining problem. I’m not sure if I need to adjust it or replace it. While I figure that out I just turned the idle up to 1200 rpms and she purrs. I would bet your cat is causing most of your problems.

 

i have similar issues with my 3.0. everything has been replaced except for the distributor. i need to get a new one and see if that fixes it. i also have a small amount of oil under the cap and a jumpy idle...

 

ok so i had the same issue with my 3.0 4runner. What it turned out to be was water in the connection for the igniter. Remembering that these vehicles are now 15 plus years old connections are starting to get loose around the wires. My 4runner woudnt idle and would die at stop lights and the only thing keeping it going was keeping the revs above 1000. Check this. A can of electrical cleaner from autozone or discount 7 dollars should help it. Then puts some silicon sealant around the top of the connection.

 

Did anyone who changed the cat, have problems with top speed before hand? My 1994 3.0 4 runner is doing pretty much the same things you are saying, but it will not go any faster than 70mph, and it takes forever to get there. Even with stock tires.

 

I was having problems getting to 55 mph even in third gear to the floor changed my cat with a high flow magniflow cat and now I can hit 80+mph and I am running 35`s with stock gears

 

I will check for wet connections.

Where do I get a high flow magniflow cat? Is it a bolt in like the original? How much are they?

 

mgnaflows are about $100, or $280 if you live in cali.......

 

I bought mine on eBay $109.00 Bolt on direct fit and got the gaskets from AutoZone it took me about 15 minutes to change it. Make sure you torque the bolts Toyota recommends 29 foot pounds. Also PB blaster works well to loosen up the old bolts.