heebeha

I just picked up a 1993 4runner with 161k miles, V6 3.0 engine. I replaced all the plugs, wires, cap, rotor, fule filter, oil/filter, PVC valve(what a btch to get to). I added an engine restore additive to the oil to fill any gaps in the cylinder walls and clean it out, Added a fuel aditive to clean the fuel since it was sitting for 2 years. It runs great now but failed the smog test. Do you think the engine restore I added to the oil screwed me up?

After failing the first time I have added a fuel additive that is supposed to guarantee I pass after a full tank of gas runs through with it and set the timing right. I bought a new catalytic converter but it looks like a big job to replace it without a torch. I wonder if it will make a difference to replace the cat convert.

Below is my failed smog test readings at both 15mph and 35mph. If anyone knows how to read this and can give me some insight I would greatly appreciate it.

%CO2
TEST RPM MEAS
15 mph 2070 14.7
25 mph 2030 14.7

%O2
TEST RPM MEAS
15 mph 2070 0.5
25 mph 2030 0.4

HC (PPM) (REASON FOR FAILURE)
TEST RPM MAX AVE MEAS
15 mph 2070 88 18 118
25 mph 2030 53 12 116

CO (%)
TEST RPM MAX AVE MEAS
15 mph 2070 .64 0.05 0.35
25 mph 2030 .77 0.04 0.36

NO (PPM) (REASON FOR FAILURE)
TEST RPM MAX AVE MEAS
15 mph 2070 508 149 518
25 mph 2030 761 144 472

Yota82

HC= Hydro Carbons. NO= Oxides of Nitrogen. PPM= Parts Per Million. High NO can usually be lowered via retarding the timing or EGR functioning correctly. High HC's (too much fuel) is sometimes a result of a bad O2 sensor and/or vehicle not getting up to normal operating temperature (not driven long enough before SMOG check or open thermostat or non-existant thermostat). Check timing and set it right, check EGR flow, take vehicle on a long drive before next SMOG check.

heebeha

I lowered the timing. It was at 15. I lowered it to 10, the specificated timing. Is there a wa yo change the fuel mixture on this engine? I think it running to rich. So you dont think the additives impacted my failing the smog test?

Crymson

Replace the catalytic converter and it should pass. NO and HC should be polar opposites, e.g. if you're running rich NO should be low and HC high if you're running lean NO should be high and HC low. Seeing as both HC and NO are above the failing rate, you are either running too rich and have a malfunctioning EGR system. Yet, it is more likely that the catalytic converter is the source of the problem.

Matthew Sheppard

93 4Runner Fail on emissions test @ NO(PPM) 15mph. Pass @25mph
Max Avg Meas
356 113 747 @15mph. FAIL
533 150 280 @25mph. PASS
Timing @ 11
any info at this time would help

Punchy

Bad CAT