running lean?

we just picked up the MM and i believe it is running lean, the spark plugs were while in color, the truck is running good but i am getting a slight pungent smell out the tail pipe, not rich gas smell. i can do basic repairs on engines but not big on troubleshooting.. i need to get inspected on mon and would like to try to troubleshoot before then. would take to a shop but cant get in cause holiday.. is there anything off the top of your heads that i can check for?

A little bit more information would be helpful. Fuel injected or carb? First things you can check for are vac leaks. Some people like to spray carb cleaner arround the engine, idle would pick up. Can hook up a vac gauge and check for 21 inhg steady. Irratic would be ignition miss and floating would be fueling. Rithem(sp?) irratic would isolate a single cyl.

sorry its a 93 mm 2.4 FI. ill check vacuum tomorrow, i picked up a haynes manual, maybe it will help some. it seems to be running great as far as sound and feel... well after it warms up for a minute or to, kinda rough, not real bad at first start up... im just trying to get a few things worked out before inspection. thanks for the response so far.

vac leak would cause your idle to be low. Sounds like the problem starts after closed loop operation. Could be your o2 sensor if not vac leak. You got a multimeter? Don't know whick wire to probe but should see switching 0.3 volts and 0.8 volts. Should sweep. Snap throttle should see it jump to 0.9 volts or something.

i do have a meter.. ill look in the haynes manual tomorrow and see what i come up with.. thanks a lot i have a few directions to go in now.

No prob.

well today i used my meter to read the dio codes, im getting a code for the barometric pressure sensor.. is that part of the mass airflow sensor? is there anything i can do to make sure that is what s wrong? its a $250 part. i still have to check the o2 sensor but im not getting a code for it.
today it is slightly rainy.. when i started it up it is rough idle, if i take for a spin it seems to "warm up" and its running fine.

I am not too sure but I think it is. I was having a problem warming up with one of my cars but it was low on coolant. Ficv not picking up idle like it should and fuel trim was a little off. You got a friend you can borrow a maf?

i think im just gonna take it in for the inspection and see what happens, then go from there.. my county just changed laws this year.. up til now all you did was pay an extra 50 a year for 10,000 lb plates on minis.. but when i went in to get my s10 plates it changed.. no way it will pass so im trying to find someone in another county to "move" in with to get residency in another county... BULL SHEIT.