I dont have an answer to your problem.....but I thought you couldnt clear a CEL if it was emissions related?? I thought I read something like that in the Haynes Repair manual.

 

When I was through it asked if I wanted to clear the code, so thats what I did after writing down the information. Presto no CEL. Don't know if it was supposed to or not but it did.

 

Here's the deal. 2002 Focus, Alternator went out the end of January, replaced by my local Ford Dealer. Last week same symptoms had it towed to my local Ford Dealer and the new alternator was bad and they replaced it under warranty. A couple of days later the CEL came on. I know this may have no connection but, is it possible that during replacement of the alternator they may have loosend a connection somewhere for the emissions. Had the code read and this is the description and code. P-0455 Emissions Control Sytem Leak Large. Is anyone familiar with this code fault, and what is the remedy or where do I look for any loose connections. I cancelled the code before disconnecting and it has been a week and the CEL has not come back on.

Thanks

Here's the deal. This info comes from a subscription-only website for professional auto technicians called www.iatn.net.

P0455: Evaporative Emission System Leak Detected (gross leak/no flow)

First, the Canister Vent Solenoid (CVS) is closed to seal the entire evap system, then the Vacuum Management Valve (VMV) is opened to pull a vacuum. If the initial vacuum could not be achieved, a large system leak is indicated (P0455). This could be caused by a fuel cap that was not installed properly, a large hole anywhere in the fuel system, an overfilled fuel tank, disconnected/kinked vapor lines, a CVS that is stuck open, or a VMV that is stuck closed.

So, that would be where to look. If you truly suspect an issue related to the alternator install, look carefully in that area for a vacuum hose that was knocked loose. However, if you've cleared your CEL and it hasn't come back: If it ain't broke don't fix it!

 

Steve,

Thanks for the advice and link. Will still look around the alternator and make sure all the vacuum lines are secure.

 

Re: Re: Emissions Control System

if you've cleared your CEL and it hasn't come back: If it ain't broke don't fix it!

My CEL came on yesterday, I hooked up the old OBD II and got the Exhaust Gas Recirculation code. I cleared the code and it has stayed off for twenty miles. Does this mean I don't have to replace that sensor/regulator thing in the headers?