My son came home from college this weekend with an issue with his 2001 Ford Escape. During normal driving (*13.9 v) and you accelerate to >3000 RPMs to pass a vehicle, several instrument lights flicker, the instrument gauges sweep full down (counterclockwise) (*19 v), take foot off the accelerator, gauges stay a zero, then within seconds they rotate full up (Clockwise) (*18 v), then within a few more second they rotate full down and then almost immediately the gauges normalize (*13.9 v). The engine never skips a beat. If you progress smoothly from 2500 RPM through >3000 RPM nothing happen. If at this point you punch the throttle the anomaly happens.
*Alternator output monitored at the battery

The engine light was not on when he came home after driving 200 miles. but did come out when he was out with friends. I checked the code and erased them and then I changed the oil pressure sensor. The engine light did not come on during the drive to get the above information.
Engine light is also intermittent and I came on during start after the sensor change. Not sure if the two issues are related.

When the engine light does locks you get these codes:
P0443 - Evap Emiss control sys purge valve
P0135 - O2 Sensor Heater cir. mal. (Bank 1 Sensor 1)
P0141 - O2 Sensor Heater cir. mal. (B1 S2)
P0155 - O2 Sensor Heater cir. mal. (B2 S1)
P0161 - O2 Sensor Heater cir. mal. (B2 S2)
Misfire, Fuel, Comp., Catlyst, Evap., O2 Siv Ser, O2 Heater, EGR
Erase the code and they may not come back for a month.

Gauge Sweep during acceleration

 

This may or may not be part of the problem, but when we get a series of unrelated problems a good part of the time there is a ground connection problem. Might not be a bad idea to check and clean the grounds starting from where the ground originates at the battery.

 

Hanky, Thanks for the reply. Good idea, we'll go through the system and check the grounds.