I have an 89 LX convertible. The Div of Motor Vehicles in my state uses an exhaust sniffer test in their inspection / registration renewal process, and my car failed :-(. I'm about half of a do - it - yourself - er, and I've been slowly working through a resto - mod on the car. I don't mind putting parts or work into the car, but I don't know where to go. Current mods: In-fender cold air intake, 73mm air meter, 70 mm throttle body, MSD distributor and wires, off-road H-pipe, single-chamber Flowmasters (sounds GREAT). The timing has been bumped up to about 11 BTDC. Before I bought the car, the previous owner 'claims' the car had gotten 24# injectors, which I've never been able to verify, although I added the proper sample tube to the air meter for 24#'ers. Also, the exhaust work seems like it was a hack job, and I think the air boss / air tube which is supposed to run to the cats was just cut off, and hangs open.
The car was overlimit for HC and CO (hydrocarbons - unburnt gas and carbon monoxide) at idle and was over on CO at high idle.
Some ideas are 1.) Gas in the exhaust suggests the car is running rich. Add an intake to feed more air? 2.) Add cats (hi-flow catted) with the air tube properly connected 3.) The car has a vacuum hiss when running - could a vacuum leak cause EGR / emissions troubles? 4.) Replace EGR, back off timing advance, return injectors to stock.
Again, I don't mind spending money on the car, but I try to do it on a budget, and don't want to guess. I also don't know another way to test besides multiple runs through the DMV inspection lanes. Ideas / suggestions?