What are the normal high and low side air conditioning pressures for a 1998 Cadillac Catera with a 3.0 engine?
It depends on the RPM at Idle speed your low side apr.. 40
and High side at about 150 at 2000 RPM LOW 22 High 230
if high is over 250 there is to much 134A in system at a
amibent temp. of 70 degrees F. RPM and outside temp effects
My 1997 Cadillac Catera does the samething! Normally can be done by the Coolant leaking ,Coolant needing to be flushed, a PCV Valve, Coolant Temperature Sensor, Themostat Sticking, oil cooler, and the list goes on. . You should most likely have a "Experienced" Mechanic look at the vehicle to do a pressure test to make sure you dont have any leaks and to see what is actually wrong.
it's your 'maf' = mass air flow sensor. easy to fix, pretty cheap at about $150 from rockauto.com or a good online source. do NOT buy from the caddy dealer! go to cadillacforums.com and either peruse or better yet, join the catera/cimarron group for some real in-depth answers to ALL things catera. trust me.