Ok, I've got an 87 Iroc Z28 with a 305. It has a bbk throttle body, msd 6al ignition control module, MSD 8.5mm conductor wires, pulstar spark plugs, MSD coil and distributor. Hedmann headers, 3 in flowmaster with no cat all the way back. I know the specs weren't entirely necessary, but maybe they'll help. oh and the car has 104000 original motor and transmission with a shift kit. I've been having a problem for about a month. I hit the gas and the car just bogs down. I let off the gas and it idles normal. I just replaced the IAC valve cause I thought it was bad. It's not throwing any code except for the lack of the 02 sensor. I'm thinking about changing the TPS and MAF just to be sure, but I've unplugged them and it doesnt run any better or worse. Again, the car idles below 500 rpms and wants to stall, sometimes it does. It's intermittent. One day it'll run fine, the next it wants to do nothing but be a piece of crap. If anyone has any input that might save me money by avoiding the guess and check method, I would be extremely grateful. Thanks

 

The bogging symptom is generally caused by lack of fuel. I have found this problem ,on several cars, to be caused by a failed MAF sensor. You say you've unplugged the MAF and TPS to no avail but try this test: Turn off engine, unplug MAF only, start and drive car to test for change in operation. Don't unplug MAF and TPS together. Your stalling, with bogging may be loss of fuel pressure. Verify pressure with a gauge, while driving, should be 43-50 psi. Check timing and advance by watching marks with a light while snapping throttle. If MAF, fuel pressure, and timing check out, suspect injectors.