failed smog test...hydrocarbons

My 93 k1500 with a 305 won't pass smog. It tests 5 points too high on hydrocarbons. I have replaced plugs, wires,cap,rotor and o2 sensor. Anyone have any ideas????

-- Message posted using

formatting link
information at
formatting link

Reply to
birdogzz
Loading thread data ...

formatting link

Reply to
Augustus

When I had to pass the emissions here, I would use a 'Diesel fuel modifier' in a gas engine. I used the Amsoil product only around test time. In fact I would plan on a tank of gas to be run through the engine before testing. I am not selling the product, just letting you know what worked for me. The first time I used it was after I failed the test, and two days later it passed just fine.

Reply to
Bill

...I used to put some octane booster in with premium, and ran it hard down some highway straights. Then took it to inspection hot, and left idling. The hotter the cat, the fewer hydrocarbons, and the residue and soot in the tailpipe has been blown out as well. Make sure the battery cables on both ends are good and clean also.

Reply to
Black Dog

Battery cables for emissions?

Reply to
Mike Dobony

...yes to make sure the ignition system as well as the electrical circuits are at their highest efficiency for proper burn.

Reply to
Black Dog

Considering your battery does nothing but charge while the car is running, I fail to see how it helps

Reply to
topprolmc

A less than clean ground can cause less than great firing and sensor inputs

Reply to
Black Dog

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.