idle racing

[peterng]

G'day,

Minor problem here, hopefully. Everytime I start the vehicle, it runs fine and then about one minute, just about time the engine hstarts to warm up (temp guage hits the lower slanted white line on the guage). the engine starts to idle high, then low, then high, then low, couple of seconds per demi cycle. then once it warms up it's fine.

89 toy pickup 22re, new exhaust, with new cat and o2 sensor (truck did this before the new exhaust went on) crank seal is leaking a bit, no codes coming up.

any tips?
Thanks,
Pete

[BlkSrx]

It could be the ECU, my truck is doing it to when i put in LC engineerings Pro Tuning Module. It make the Ecu think that it is colder then it is, to put in more fuel. after my truck is normal temp. it is fine.

[rogerman]

egr valve?