Codes P0452 and P0453

**vncj96** · 10-29-2009, 08:58 PM

I have got the 453 before but this is the first time for the 452, do I really need to change a sensor? Will this low input on the sensor really hurt anything?

**Jimmiee** · 10-30-2009, 08:17 AM

It will keep your check engine light active and will keep your OBD checks incomplete. The 452 is low input and the 453 is high input. So something is screwy with the sensor. Have you ever changed it?

**vncj96** · 10-30-2009, 08:34 AM

Have never changed it, I reset them last night and they havent come back on yet. Wouldnt even know whee to start with them.

Jim, is this the correct one?

http://www.oreillyauto.com/site/c/de...PartType=C0033

**Jimmiee** · 10-30-2009, 02:34 PM

Originally Posted by vncj96

Have never changed it, I reset them last night and they havent come back on yet. Wouldnt even know whee to start with them.

Jim, is this the correct one?

http://www.oreillyauto.com/site/c/de...PartType=C0033

I've never changed one of those so I can't answer your question. Maybe someone else has?

**vncj96** · 11-02-2009, 04:27 PM

Ok so the light came on again and then went out by itself, and I have noticed my MPG has dropped for this tank, does this sensor take the place of the fuel pressure regulator or what does it actually do?

**MrShorty** · 11-02-2009, 05:24 PM

The EVAP system is completely separate from the fuel system, so it has nothing to do with the regulator.

If you follow your fuel lines, you will find three lines off of the tank: 1 is the fuel supply line (from the pump to the engine), 2 is the fuel return line (from the regulator to the tank), and 3 is an EVAP line. As the tank breathes (so you don't a vacuum or pressure built up in the tank), the EVAP systems job is to make sure the gasoline vapors from the tank end up going to the intake so they can be burned. The pressure sensors are there so the computer knows if the EVAP system is doing its job correctly.

I haven't had to do anything with my EVAP system, yet, so I'm not real familiar with it either. Go down to your library and find entries 2 and 3 in the following list http://ipac.selco.info/ipac20/ipac.j...ll&Search=Find
Look through the Mitchell manuals and see if they have the "light truck engine performance, diagnosis, and troubleshooting" manual for your year (or near your year). In there, you should find complete diagnostic and repair information for your codes.

**Jimmiee** · 11-03-2009, 10:40 AM

Originally Posted by vncj96

Ok so the light came on again and then went out by itself, and I have noticed my MPG has dropped for this tank, does this sensor take the place of the fuel pressure regulator or what does it actually do?

Short Answer: The sensor measures pressure inside the tank. It tells the PCM there is a leak if it sees one.