97 Tacoma Poor Engine Performance at high speed

All, My 97 3.4l Tacoma 4X4 began experiencing poor engine performance at higher speeds (65-75 MPH). A description of the problem is the engine seem to start choking for fuel, and begins to shake. The last incident the check engine light came on and I limped it to my local garage. They ran diagnostics on it and determined that cylindar 5 was mis-firing. The replaced the Ignition coil, wires, replaced the spark plugs, cleaned the fuel intake and air intake sytem. I drove my Tacoma the following day and had the same issue at high speed. Has anyone else had this issue? I've already spend $650 and would prefer not to spend that much again for a simple fix. Thanks for your help.

 

check the wires that are grounded to the intake manifold where the diagnostic port is it may be a lose ground i had same prob.

 

I had the same problem, at about 140K miles. My Mass Airflow Sensor was going bad, and couldn't keep up with the engine at high speeds/rpm's. It also set mis-fire codes, which is pretty common with MAF failure.

 

I really appreciate the input. Do you know where the Mass Airflow Sensor is located?

 

Would you happen to know where I could find instructions on how to replace the sensor?

 

It's as simple as unplugging it, removing the two screws that hold it in, and then reversing the procedure.

 

also you may want to sea foam your truck