I failed my smog test for the 3rd time 1995 525i

[aspenpup]

I failed my California smog test for a 3rd time this morning Help me figure this one out

California HC standard for this car:
15 mph = 81
25 mph = 40

1st test (running mid-grade gas)
15mph = 54 (ok)
25mph = 42 (failed by 2 points)

2nd test (after running bottle of Seafoam and then refilling tank with premium)
15mph = 132 (failed by 50 points)
25mph = 40 (ok, barely)

3rd test (after checking all vaccum hose, and filling with regular unleaded)
15mph = 81 (ok, barely)
25mph = 49 (failed by 9 points)

STOMP test shows "no codes"

If CAT or O2 sensors are not working, shouldn't I have error codes? Just wondering what can be wrong. Obviously fuel type makes a difference. The plugs have been replaced already. Car idles and runs perfect.

Blue book value is $2-3k but my interrior is looking bad so I would be lucky to get $1500-$2000. That's a moot point because I am responsible for making this thing pass smog if I sell it. The State of California will buy for $1,000 just to get it off the road. Too bad since this still looks and runs good but I don't want to take to a shop and have them charge $400 to do something and then my smog number still fail.

Any ideas?

[Bruno]

A high HC reading is the result of poor combustion. The most typical cause is a poor ignition system. HC is nothing more than fuel that makes it out the tailpipe without being burned.

I would start by checking all the coils, replacing the spark plugs and checking for vacuum leaks.

More info here: What causes high HC. What causes high Hydrocarbon - SmogTips.com. Failed HC Emissions. Why did my car fail the emission test for high HC emissions. What is HC. My vehicle failed the emission test for high Hydrocarbons. Why my car produced high HC. Hi (http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm)

I had the same problem with my 92 525i, and the guy was nice enough to run the car in a different gear and play around so it barely passed HC...

[Tiger]

So close... Air filter clean? Did you clean your MAF sensor with MAF cleaner? Make sure the duct from MAF to intake is good with no hole (remove to inspect)?

Oil Change? When is the last time you did this? Dirty oil is also higher emission.

I'd suspect dirty fuel injectors but to pass the inpection, I'd dump in fuel drier to cheat.

if your cat and O2 is bad, you wouldn't get that close of reading... would be way off.