Gonna start a new thread since I wrapped up the AIR pipe installation thread and it has not fixed the underlying problem.

I'm in the uncomfortable position of having a 1996 pickup and living in an emissions county which requires an OBD II dump to pass - which mine won't at the moment :/ My tags die in September and I need to fix this problem FAST and get the truck emissions tested before I return to college mid-August.

What I know: my CEL is lit up for three codes: a P0411 (Secondary Air Injection Incorrect Flow) as well as lean codes for both bank 1 and bank 2.

I am figuring the lean condition might have something to do with the (in my opinion) slightly higher than normal idle (900 - 1000 RPM) as well as a slight hanging idle (when I push in clutch, engine will not rev down immediately, but will rather stay at crusing RPM until I grab the next gear and release the clutch). From my experience on the forum, this may be any number of vacuum lines leaking. I had the throttle body off and checked the clearance around the blades - I could see some light peeking thru but am not sure what is acceptable and what is not - if anyone can provide pictures I could compare to mine and discover if that is the issue. I've already tried the old starting fluid/propane/flammable solution sprayed around gasket surfaces on the intake - so far no change in the idle. Truck does idle smooth, just a tad high in my opinion.

As for the P0411, I have NO earthly idea what that might be. I was unaware that the truck could even detect Thermactor flow but maybe this '96 is more advanced than your average 9th gen.....

Like I said, I'm sorry because I've probably got another thread or two about this issue, but it's now or never, I've got just over 1/2 month to fix the issue before one more 9th gen pickup gets taken off the road for the forseeable future