1982 Fbrd se, 305 4bbl. All stock. Car never failed tests before this year (I'm the owner for 18 of the 22 years).

On 1st test, NOx was 1200, 700 is limit. Replaced EGR valve. 2nd test, 1700 readings. As in other threads, DMV is recommending replacing the cat conv 1st, then doing the O2 sensor, checking timing, and cleaning egr passages.

Car purrs like a kitten, except for recent problem where idle suddenly kicks up while either driving or on restarts to 1300 or so, and won't kick down until car has been shut off for more than 1/2 hour. Choke light comes on when idle jumps, one mechanic couldn't find the problem, but traced the light to a short in the dash and unhooked the connection to the a/c which raises rpm when turned on. I think he was clueless.

Any help on either and/or both of my problems would be greatly appreciated.

Thanks, Keith

 

It could be the cat but I would go for the cheaper options first. This is what I would do first:

O2
Pcv valve
spark plugs..if not, check all of them to make sure they are ok
plug wires.....unless new or in good shape
distrib cap and rotor.....unless new or in good shape
Definately clean out the egr passage(s)

From here run it through to see if it will pass. As a last resort swap out the cat with a high flow one. I probably missed a few things but it's a good idea to start small before you go to big prcey items.

Good luck and hope that helps.

 

NOX are produced when the combustion chambers temps get too high. The EGR valve is what is used to control this so Id check it out first of all, possable broken vacuum line to it by your description.

 

I've seen this stuff called garenteed pass or sumthin. It's supposed to be added to your fuel to make sure you pass. I'm not sure what your options are but if your willing to take the risk of possible engine damage (I have no clue whats in this stuff but im almost positive its not good) then you may want to give this stuff a try. Depending on the people running the place an extra 100 cash to the guy sometimes ensures a pass. (had to do that with my dad's 87 pickup that had no exhaust from the collectors back

Good Luck

 

Move to SC!!!!


Ed

 

When I failed, I was twice the limit, I did, plugs, wires, pcv, rotor&dist, o2, air filter recharge (K&N), a bottle of Seafoam in the brake booster line, then the EGR. went back and was half the limit. so one of those things or all of them combined fixed the problem.

 

Whats the timing set to? It might help to knock it down a little bit.