EACOOK1

Hi guys, after 2 months worth of smog check issues I finally got my 4runner to pass today. I will try to keep this short but I wanted to put this out there to help anyone else having similar issues.

A little back ground on the 4runner. I rebuilt the engine about a year ago. Balanced, entire assy. had the heads completely ported, intake, exhaust and bowls along with the intake manifold. I installed thorley headers, new cat, and kept my old flowmaster.

Fast forward to smog time a couple months ago.
Failed the first test. HC and NOx were high.



Before the second test I replaced the cap, rotor, checked timing, replaced all old cracked vacuum lines, replaced vacuum modulator and 02 sensor. I went thru every check of the egr valve, vacuum modulator, pair valve, checked all the VSVs etc........
Failed again. This time just on NOx


What the heck. So I took it to a smog repair shop only to have them tell me my headers were the problem and they would have to re-install my stock manifolds at a cost of $800. Well that's not going to happen.

So, I have always felt the truck was running lean so after much reading about adjusting the AFM I decided to try it. I richened it 3 clicks. I also took apart the egr to make sure there wasn't too much carbon build up and found that it was fine. I left everything else alone, well the third times the charm!



So it barely passed on HC but the NOx was well below the limit. I could probably lean it out one click next time I have to smog it. I ran the numbers thru the Lambda calculator and wrote the the results at the bottom of the last print out. It looks really close to Stoich so I am going to drive it like this for awhile until I can take it to a DYNO and see what they get for AFR.

Anyway, super stoked to have figured this out, and I owe it all to all the contributors of Yotatech! Thanks guys.