1994 camaro z28 A4 doesnt pass smog. need help
 

I took my camaro to a smog star station and it didnt pass smog, surprisingly... off the top of my head i know it needs a new catalityc converter....a tune up...spark plugs, wires...anything else? i will post a picture of my smog results. but for geneal...my HC (PPM) max is 58 i was "125"....my CO (%) max is .34 i was ".93" .. my NO(PPM) max is 483 i was "1906".. those results are the 15mph test. ..and my registration is about to expired..ugggh. let me know for those of you out there. my amounts are basically double what theyr suppose to.heeeeeelp :(

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

here they are

https://www.camaroz28.com/forums/mem...-scan-5406.jpg

https://www.camaroz28.com/forums/mem...-scan-5406.jpg

thanks for ur help!

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

Those numbers are real close to what my '94 did on the AZ emissions dyno. They run your car thru all 6 gears over here.

My cat is just a shell, and doesn't reduce emissions at all. I ordered a new cat yesterday,so I don't have new numbers yet, but I'll bet it passes, this time. It looks like your cat isn't working either. Those numbers are pretty high.

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

yes someone replied! whoo. lol. thank you kevhogaz, i dont feel alone in this.lol. well ok cool, that would be awsome to know how much ur numbers change after that. yeah my Maro isnt trowing any damn codes at all, thats why i got all this went to oreillys and purchased the following.. Fuel cleaner, 2 BOSCH oxygen sensors, ACDELCO spark plugs, k&n gold oil filter, BWD egr valve, MOBIL1 synthetic oil, total of $254.00 and ordered a new cat from meineki which was $289.00... comes down to $543.00 ((siiigh)) . il have the cats installed friday.. everything else will be put on that same night.. my deadline is this 18th coming up.. if it doesnt pass... i have no clue. Put it on non op til then :/

p.s. what is this denatured alcohol that "helps" other cars pass??? would it work for mine???

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

I'd do the cat first, and retry unless you have a limit on how many times you can go thru the lane. If it passes, take all that other stuff back. You might not even need it.

I've seen guys use the alcohol in bikes, so I'd have to imagine it would work in a car, but I have no idea how much you'd need. Like I said, try the cat before you go crazy with all this other stuff. It'll probably pass, and you wont have to worry about it anymore.

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

Many people have bad results with the bosch o2 sensors in our lt1 cars. Ac delco is the preferred o2 sensor. I know nothing of smog testing sorry cant help with that

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

Whats the problem with the Bosch O2 sensors? Do they show lean conditions, or something?

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

Not real sure just alot of people report issues with them. There are several threads if you do a search. I think they arent as responsive as the ac delcos. Some people dont have trouble but many do so they are advised against.

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

The post on the bottom of this link explains it I guess lol. Its just not wise to put something that may not help in the mix when your trying to solve other problems. https://www.camaroz28.com/forums/lt1...sensor-773015/

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

Gentlemen BEHOLD!!! .My camaro just passed an hour ago! alot of people dont follow up , so i will!! turns out my cat was empty inside, hollow!! the car needed a tune up anyways so i installed everything, except for one 02 sensor which seemed to be stuck :( , but the star smog station gave me the run around, they wanted the invoice, the serial number had to match and what not. surprisingly they told me that i should clean the egr valve which is the reason why i came close on the NO(PPM). im like awww i forgot to clean it kuz i replaced it too!! anyways im so happy , $800.00 later i will be receiving my sticker :) and yes registration was flat 100.00. lol. wow, thanks for all your guys suppport, these are the results and hopefully when someone has this problem they have hope from this post..my camaro does have a whopping 163k miles on it! thanks everyone!

https://www.camaroz28.com/forums/mem...hoooo-5408.jpg

https://www.camaroz28.com/forums/mem...hoooo-5408.jpg

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

dont know why it came out small , but il write them out

15mph HC(PPM)
Max 58 MEASURED 13

CO(%)
Max .34 MEASURED .02

NO (PPM)
MAX 483 MEASURED 479

25MPH HC(PPM)
Max 34 MEASURED 14

CO(%)
Max .32 MEASURED .01

NO (PPM)
MAX 494 MEASURED 300

The NO is hella close tho...lol

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

You wasted $800, a gallon of dentured alcohol would of solved that issue. I am sure some tree hugger will disagree.

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

actually i didnt use any alcohol.ppl kept telling me i should get bigger injectors .kept pushing me away from it. so i was like ehh, im not going to mess up my car. but yeah definitely money well worth it. . And to those tree huggers out there, they eat salad, greens.kale seaweed..stuff that contradicts theyr whole saving the planet...lol

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

You only use a small amount of alcohol, not an entire tank full. As soon as you leave the inspection station, you fill the tank with gasoline again.

Re: 1994 camaro z28 A4 doesnt pass smog. need help
 

The idea is to have a quarter tank of gas that should be 4-5 gallons then pour in the gallon of denatured alcohol. Go to the inspection station, make sure you gave your car enough time to warm up before inspection and get it inspected. It will pass with flying colors, I know because I ran my z28 through it with gutted cats and passed. At the time I did not know it had gutted cats, I just found out the other day when I pulled the exhaust off. After you completed the inspection go to the nearest gas station and fill the car up with gas to dilute the remaining alcohol.