kushiel

I haven't posted much but I am a year into owning/overhauling an nice 87 22RE 4Runner. The first year I failed the emissions test but found a really dirty air filter. Swapped that out and all was good.

A year later, new emissions test and my HC is high on both the low and high RPMs. Like 120 over on high and 40 over on low.

I put in new spark plugs (NGK copper), a new O2 sensor (Denso), new air filter, and replaced the rotor and cap. The plug wires were in good shape.

Things got worse.

The high RPM HC is reading 1000 and the low RPM is 220 (20 over).

Here is what I've done so far.

Jumped the diagnostics - came back all clear

Idles at 750 RPM, same with the AC on. I did have to make a idle and AC idle adjustment about 2 weeks ago. Not sure if it's related.

Visual inspection of the vac lines and hoses. All good there.

New PCV

I am getting around 20 MPG mixed highway/town with a full load in the truck.

No issues with misfires, acceleration.

Today I swapped the old non-Denso O2 sensor in. Checked again, same results.

I was thinking about doing the following:
Double checking the spark plugs
Amp meter on the TPS and AFM
Recheck all the vac lines.

Any suggestions? The guys at the emissions place were pretty baffled by this.

kushiel

Quick update.

At 2500 RPMs I get a popping/bumping noise out the back.

I had the valves adjusted a year ago 'cause of the new block that was put in. I am wondering if I need to adjust the valves again?