With a GM-type TBI system, anytime you make significant changes to engine airflow, whether it's intake or exhaust, you need to readjust the minimum idle air/speed settings & T.P.S voltage.

See this recent post for more info on the topic:

http://www.4x4wire.com/forums/showf...mp;amp;sb=5&o=14&fpart=1

Cheers..........ed

'90 Troop 3.4 LS
'89 Troop RS (Has Valve Issues, needs Counseling)
HI, I'm Ed and I'm a Trooper-holic!
Keep On Troopin'......