Failed smog

[94xjstud]

Update . . . ish. After I noticed the crack in the header I welded as much of the crack as I could get to, top and bottom, took it back for a resmog and it did alot better but not quite. My NO number was around 630 instead of the 860 it was at. I think I found the main problem but could not completely weld the crack closed without removing it. Looks like I am going to have to suck it uo and buy a new one.

The guy is really cool and said I should SeaFoam it too and try to remove any carbon build up, but cautioned me that it may get caught in the CAT. I want to foam it, so does anyone have any suggestions or links? I hear putting it into the intake manifold is the best but I am not sure where to do that at.

 

[Bryan C.]

Update . . . ish. After I noticed the crack in the header I welded as much of the crack as I could get to, top and bottom, took it back for a resmog and it did alot better but not quite. My NO number was around 630 instead of the 860 it was at. I think I found the main problem but could not completely weld the crack closed without removing it. Looks like I am going to have to suck it uo and buy a new one.

The guy is really cool and said I should SeaFoam it too and try to remove any carbon build up, but cautioned me that it may get caught in the CAT. I want to foam it, so does anyone have any suggestions or links? I hear putting it into the intake manifold is the best but I am not sure where to do that at.

Try running your most recent test numbers through the lambda calculator again and see what is shows. I still say the cat is dead. The exhaust leak was just making the emissions worse.

 

[huitzi]

Im a smog tech, you need a new cat. 4.0s dont have EGRs and ignition timing isnt adjustable.

 

[Boatwrench]

My results, 1988 4.0L w/ 5spd


@ 15MPH = 1.002 Ratio 14.73
@ 25mph = 1.002 Ratio 14.74

The 15mph HC ppm maximum allowed is 86 and 86 ppm is what was measured...so just passed.

 

[Johnnie Walker]

I know several people that have exhaust leaks, mostly manifold, and they passed just fine. You can pick up a new cat as low as 40$ ish ... www.performance-curve.com

Im a smog tech, you need a new cat. 4.0s dont have EGRs and ignition timing isnt adjustable.

Up to 90 (renix) they did have egr actually.