1998 Toyota Tacoma Backfiring Upon Acceleration

We have a 1998 Toyota Tacoma TRD v4. Truck cranks and idles fine. But when you push accelerator it sputters, spits and backfires through the exhaust. We replaced fuel filter, spark plugs, wires were changed last year. We also added a fuel additive in case water was in the fuel and nothing is working. Any ideas of what it could be? We are thinking it may be the injectors...

 

Is the check-engine-light (CEL) on? If so, get the code(s).

Get the sensors checked : CAM, crank, TPS, etc.

 

Light is on, a friend is stopping by later to check the codes. Truck smells like its flooded when it runs.

 

According to the code, it is throwing a fuel pump code. But you would think the truck would not idle at all if it was the fuel pump?

 

What does the actually code say about the fuel pump?

 

At idle, the motor uses a tiny bit of fuel compared to any other throttle position.

 

lets us know the codes first. it's very likely you have a rich mixture. but you may have a bad exhaust valve or dirty valve seats allowing fuel to seep into the exhaust while it's firing.

compression test to disprove the valve issue.

 

Have you changed out your o2 sensor? Make sure you maf is clean. Do you have anything to look at you o2 voltage or fuel trims?