NOx emissions failed - help

[jboates]

I'm a 'little' new to this forum /emoticons/[email protected] 2x" width="20" height="20" /> but I have a tech question for you all. I recently purcahsed a '90 Bronco (351w if that helps) and failed the NOx emissions test. Everything else is fine. The shop I took it to wants me to pay an $85 diaog. fee just to find out what the problem is. Then I'll have to pay them to fix it. Just wondering if you all know of any way around this problem. (I'm thinking it's my cat. converter since it's around 15 years old..I'll have to check the receipts and see if the previous owner ever changed it.)

I also tried this stuff called Bardol that garuntees you pass emissions. Yeah right. (they'll give ya $10 if you don't) If anyone here has used this stuff before, I guess it works because I had about 5 feet of smoke coming out of my exhuast when I revved the engine. It soon cleared up (and I guess burned all the crap out of wherever) but it was the weirdest thing I've ever seen. It looked like a damn fog machine.

Thanks guys. Keep up this great forum.

- jboates

 

[stevenschi]

well, when it comes to emissions, anything can be considered a culprit. yeah, a cat convert. may be a factor, but there's alot of components on your truck that could be failing your test. many are simple and easy to check and replace. first, on your fan belt there should be a 'smog pump'. make sure it is not binding and that its connections are secure. also the oxygen sensor could be to blame, b/c it goes before the cat conv (usually). it is on the exhuast pipes near the muffler and just screws in and out ($20-$30) also, the pcv valve on the right rear of your engine may be clogged up with crankcase oil. check it. if none of this works, let me know, i have more suggestions but these are the most likely from my experience with my 1987 truck passing georgia's emissions with flying colors.

 

[jboates]

thanks a lot. I will check these out and let you know. thanks again.

 

[Seabronc]

Two functions are directed at NOx production. The Thermactor system and the EGR system. As Stevenschi said a lot of things have an effect on them.

Good luck,

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