2000 Mazda b2500 • 4 cylinder 2WD Manual • 1 miles

I have a 2000 mazda single cab b2500 with two perplexing problems.

1. Heater and A/C air flow becomes restricted to the point of hardly any air moving from any vent in the truck. This happens in about 45 minutes of driving and seems to stop if I park the truck for awhile and let it cool down. I checked the fan motor and it works correctly. It seems like there should be airflow from at least one of the vents no matter what so im confused.

2. The check engine light has been on for a long time and when I plugged it in to a computer it said that the engine was "running lean on bank one" I replaced the O2 sensors and the fuel filter it worked for awhile then same problem agian, next I brought it in to a dealer and they told me that my fuel presure regulator was bad, I replaced that also and it diddnt change anything, the only thing that works is removing the fuel filter and then sticking the same or a different one back on, although it doesnt really seem to matter if its new or old so I dont think that the filter is actually getting dirty.

I hope that someone smarter than me can answer these questions for me.
November 18, 2010.

Your A/C evaporator is probably freezing up, causing your loss of air flow there.

The lean condition is just going to have to be figured out by a competent technician. Vacuum leaks are a very common cause of that.

Nov 18, 2010.
Yea that black ac canister is freezing up, what does one do to fix it.

Nov 18, 2010.