I also have a P0452 code on my 2004 Blazer that I recently purchased and have been trying to find the problem. Replaced pressure sensor, Evap vent solenoid, replaced canister hose's, removed fuel tank to get to lines and put it back, *now I also have a P0101, P0106 and P0452. Not sure what to do next. Need to get Ohio Echeck by 11/30/15. Could anyone please help resolve

 

After a good visual inspection, always diagnose and repair the first DTC that is retrieved. After the repair, clear all memories and perform a drive cycle to confirm your repair. If the light comes on before, during or after the drive cycle is completed, retrieve the DTC's and diagnose the first DTC that is retrieved and repeat the process above until the light no longer comes on. Here is a link to the GM flow charts: https://blazerforum.com/forum/tech-a...agnosis-26408/

 

Today I removed the fuel tank again to check to see if maybe a line or wire came loose or got pinched. Remove fuel pump to check seal, put tank back under truck and reconnected all lines and hose's, started up engine and still had the P0452, P0101, P0106 scratching my head I looked under the hood and found the MAP sensor out of the hole, maybe from a backfire when first starting engine. Reinstalled in the intake manifold started engine cleared codes and the P0101 & P0106 went away. Still need to find what is causing the P0452 the only thing I haven't checked is the purge line & solenoid