So life happens and my firebird has been sitting for the last year. This weekend I decided I finally wanted it back on the road so I charged up the battery put some premium gas in it, and drove it around the block a few times. It seemed to be running pretty decent and threw no codes, plus the car is not tagged due to not getting the smog done on time, so I figured I don't want to risk driving it too much and took it over to a mechanic shop that also does smog. They got it to pass last time it needed smog with no issue. This time to my surprise the HC reading is insanely high and also the CO is high causing the car to fail as a gross polluter. It also got an error code of P0152 during the smog run.

Did I mess up by not driving the car more and getting all the old gas out of the tank? I told them to go ahead and take a look at it to figure out why its not passing, but I figure they are not going to know and just assume it needs an oil change and wires (which it honestly probably does but I'm pretty sure there is barely any miles on the car since I last did plugs and wires.

Anyone have any insight on why its giving these readings? Guessing the car is running rich, which it always kind of has but I have always been able to pass smog with it. Looks like they really didnt let the car get up to temp, could that be a reason given the high readings or is it something else? Car is modded with LE1 heads, 224/230 cam and also a mail order tune done by Solomon.

Ive read that I should get rid of all the old gas and then put a few gallons of regular fuel along with some of that lucas fuel treatment?

 

The trouble code is for a bad O2 sensor which can be a good source of your problems. Even if oil has no miles on it, if it sits it will become contaminated. What I would do is change the oil, plugs, change to Denso O2 sensors, put in fresh gas, seafoam the engine and run it like a scald *** ape to clear out/get the catalytic converters hot before you take it to get tested again.

LOL @ "gross polluter"

**** California

 

hum...wake up a heads/camed, aftermarket tuned 25+ year old car with old gas and oil and codes and you failed CA smog. Not trying to sound like a dick but that is a sure-fire way to fail CA emission test.

So now that you are in the system as a failed car you want to be really buttoned up for the next test. This can be expensive if you wind up replacing CATS (yes CARB CATS are stupid $), which may need to happen in addition to replacing 02's, fix EVERY vacuum and exhaust leak (likely have them) which caused PCM to see air so more fuel is added which in time kills CATS. Plugs and wires if over 50k mi.

Clearing codes will also clear al IM monitors so you need to do SEVERAL drive cycles (read hundreds of miles) and when you do take the car in bring it in hot. You want those CATS as hot as you can get them. I have "read" (cough) that a tuner can set all IM monitors to read ready all the time. Also read people having that done so they can swap in a "smog tune" PCM with closer to stock timing and fuel curves and engine fan temps so motor will run the 200ish degrees GM set them up to do for emissions...something I read about so ask your "tuner".

fail twice and you get a note to see the referee...you never want to see this guy.

 

I def agree with you and if I was a bit younger I would have spent some more time messing with it. But honestly im pretty sure I stopped driving it just because the last time I smogged it, it was a big pain in the ***. Figured taking it to a mechanic right away would be the smart thing to do. Honestly pretty annoyed tho since they told me it failed smog but they could get me into the garage right away for diagnostics. That was yesterday at 11am. Still no word so far. I mean I can do an oil change and plug/wires myself if needed. But I really want them to figure out if there is any exhaust or vacuum leaks and figure out the 02 sensor since they can get the changes up on a computer and tell if its reading right or not.

 

ok here are the results of their expensive *** diagnostic.

So I plan to replace the #7 plug and wire and will probably replace both upstream 02 sensors with the Denso ones. Going to run some seafoam through the engine and I also bought some lucas fuel treatment, although I guess the seafoam would do the same thing if put in the gas tank. Going to do that and drive the **** out of the car this weekend. Is there anything else I should do? How will I know its fixed? There is roughly 900 miles on the engine since I last smogged the car 3 years ago. Car has really never felt any different which is odd. So what do you think are the possibilities for the head damage or cat damage?

Edit: Plug wire #7 was not burnt at all. the plastic around it was melted since it was close to the cat. Wire looks 100% fine with no marks. So I routed the wire away from the cat a bit better and changed out the spark plug. Old spark plug honestly looked brand new. Ill post a pic when I get a chance. But I know these plugs and wires have def less that 900 miles on them. Put 40 miles on the car tonight and it feels like its driving fine and there were no codes thrown. Going to add seafoam tomorrow and continue to put miles on the car. Hopefully I can pass smog in the next week or two.