CEL and what could be the cause/solution

[PGTBrow]

Ok so the CEL came on for the first time in 70k miles. I scanned and it and its comes up as:

P0451: Evaporation Emission Control System Pressure Sensor Range/Performance

At first I assume its the gas cap. Re-tighten and clear the code. Back on next day. I then fill the tank with 93 just for s**** and giggles, clear code, back on next day.

Sooooooo what could this code be for? Is there a little POS sensor in the tank that needs changed or do I just need a new gas cap?

Saw this online, any validity to this?
http://www.autoserviceprofessional.com/article/92624/plugged-mazda-ftp-breather

 

[DrWebster]

I'd start with a new gas cap, it's the cheapest/easiest solution.

 

[flatlander937]

I'll look up the code info tomorrow and see if there are any hits on my tech site at work.

 

[jasyatz]

Check under the rear of the car where the giant canister is to the front of the car from the rear tow hook.. See if any of the hoses are hanging off the canister or cracked. The canister is is a very vulnerable spot to road debris should you happen to run over something large(ish).

That canister is the evap recirculating canister and if it loses pressure and/or vacuum, it will set all sorts of funky codes..

 

[PGTBrow]

So far on the internet it seems like this is a TSB for the 2011 model year. Might just go buy the new hose and clip from Mazda and fix it myself.

 

[flatlander937]

Yep checked and its a TSB.

You can make sure the sensor itself is good by back probing and checking voltage at the sensor. Voltage range is listed on the TSB above.


I'll add that there is zero chance its the gas cap.

 

[PGTBrow]

Lol ok thanks man. Yea imma head straight at the TSB for this one.