failed inspection, please help

[LotsaSpeed]

I went to get my inspection and my nitrogen levels are too high to pass. All my mods are in my sig. Any help would be appreciated. I have replaced my cat fairly recently. My spark plugs are pretty old and my O2 sensors are original. Would it help much if I changed these parts out? If I do change the spark plugs should I go with a cooler plug to help bring the nitrogen levels down? Anything else you guys can suggest would be great. Thanks.

[dstrbd1]

i know it sounds wierd, but another guy from the fort worth area had this same problem. changed his egr, pcv, plugs and wires, o2 sensors, still failed on the NOx. went to a different shop and they found that the first place had put in the wrong weight for the car, so the computer standards were set for a much smaller car. they punched in the right weight and boom, pass. not saying that it's the same in your case, but worth a try.

[LotsaSpeed]

When I change my plugs, should I go to a cooler plug to help pass the NOx test or will the bosch platinum +4 be fine?

[dstrbd1]

go with some ngk's if ya can find them. you'll prolly have to have o'reilly or someone order them for you. they're a really good plug and should help with emissions. check your egr and see if it's gunked up or anything, and if it's been a while go ahead and change the pcv. that should help without costing a whole lot.

[Brett Garret]

I'm the guy who failed 4 times [img]smile.gif[/img] . Anyway, NOx is controlled by your cat and EGR. I had changed EVERYTHING (Bosch o2 sensors, Taylor wires, AC Delco Rapidfire plugs, new PCV valve) and was still failing NOx. So, I took it somewhere else and found what controlled NOx and what I could do to help it. My cat was a brand new Catco and my EGR was nasty so I had that cleaned. They also said the weight in my car about a half ton off [img]graemlins/omg.gif[/img] . So they retested and I passed with AMAZING numbers. My advice to you is have your cat and EGR checked. The tune-up idea is good to go as well...my car feels better than ever.

[3.4pwrV6]

My car had the same situation, but I wasnt off by too much with the Nox, I just changed my O2 sencors and I passed with flying colors, everything went down. I would suggest just OEM plugs for the time being and check into new Bosch O2 sencors. If it fails again go the ERG route that migt have caused it the whole time. and while your at it try pouring a botle of rubbing alchol it to the tank then fill 'er up drive it for a while open it up a couple times to clean some of the crap out then change the oil as well. That might help it some, after the O2 sencors of course.

[CARdiac]

I posted that I had failed as well. I took the car for a 45 min drive on the hwy keeping in it D not OD (rpms around 2500)and passed. The cat got nice and hot. Go to CamaroZ28.com and search for my post, the guy who replied is a smog tech in CA and should be able to help you.

[CrazyBosnian]

Ok, i'm an emission inspector here in ga, so i can give ya some tips... Brett Garett is right. Plugs, and everythinh else doesnt really have **** to do with NOx... Its all in your EGR, CAT, and timing... Since you have had a new cat put on not too long ago, i'd say clean, or even change out you egr valve and you'll be set. And oh yeah, drive the hell out of the car before you go there, warm it up good... [img]smile.gif[/img]