pathway

4.6L V-8. Since last Labor Day, truck intermittently jolts, the RPM needle spikes then drops, the check engine light blinks for a second then goes off. And everything goes back to normal driving. Codes won't show up since check engine light doesn't stay on. Done a full tune-up, new ball joints, new computer, new heater core, new fuel pump, new crank sensor, flushed the radiator. Anybody got any idea what's going on? Two different shops have no idea.

whomrig

Have you checked every electrical connection on your rig? From your description here it sounds to me like a bad connection (or ground)

Jbrew

Or it could be the MAF. Is it just the needle that spikes or does the engine actually rev up?

me1234

I agree with the MAF. Mine used to stall at red lights, and if it didn't would spike up. I cleaned the MAF, throttle body, and replaced the air filter. Boom, problem solved.

pathway

Checking the wiring has not been done; guess that's next. The engine does rev for just a split second along with the needle spiking.

Jbrew

BTW- the engine light doesn't have to stay on to produce a DTC. A blinking light usually sets one on theses Fords. It's unusual for it not to. Saying the engine light has to be on sounds like something Auto Zone would tell you. Absolutely not true.

pathway

Okay, so today, the check engine light STAYED on and I got a code: P0153, Bank 2 Sensor 1 to replace the O2 sensor and reprogram the ECM. Is there any way to know whether this is really what's going on, as opposed to a wiring problem? From what I understand, that code can also mean wiring issues.

Jbrew

Reprogram the ECM? Yea, these have PCM's and I hope you didn't reprogram that, since you were unaware of this. I don't know ow you could actually.

You check the wiring harness first for problems, replace the sensor after the harness PCM has been confirmed good.

Jbrew

pathway, - Make sure the ground is good like whomrig posted above ^^.

The PCM uses the ground on the firewall (pass side right in the corner adjacent from the battery.)

ametzker

Yeah kinda sounds like a loose ground to me or a connector corroded or loose.