I have 2007 mazda 3 and the cel came on. I replaced the leak detection pump on the advice of 1 service tech but the cel came right back on after about 70 miles of driving. The car runs fine except when I put gas in it and then it is very hard to start. The first tech says the purge soleniod valve is fine and I had a smoke test done on it which produced no results. Anybody have any ideas?

 

whats the cel code

 

+1, go to an advance auto parts (or similar) and have them pull the code. That way you actually know what the issue is.

 

P2187

 

P2187 Fuel system too lean @ idle

Possible causes are:

• Misfire
• Front HO2S deterioration
• Front HO2S heater malfunction
• MAF sensor malfunction
• Pressure regulator (built-in fuel injection pump) malfunction
• Fuel pump malfunction
• Fuel filter clogged or restricted
• Fuel leakage on fuel line from fuel delivery pipe and fuel pump
• Leakage exhaust system
• Purge solenoid valve malfunction
• Purge solenoid hoses improper connection
• Air suction in intake-air system
• Insufficient engine compression

No idea what you replaced but its not even close to fixing the problem. This is not an easy fix, take it to the dealer.