Cleaned MAF and TB, now CEL

[Clayton]

Hey guys, had my truck for a little under a year now and slowly but surely have been catching it up on overdue maintenance. I've often found the solution to my problems on this forum, so thanks for that

So, onto the problem at hand. My truck recently started to have a surging idle. I changed the air filter and cleaned the MAF and throttle body with the respective products from CRC. Truck seems to run great now, except it's throwing codes:

p0172 system too rich bank1
p0443 evap emission system purge
p0401 EGR flow.

What gives? Did I damage the MAF? I disconnected the batter for 30 minutes to try to clear the stored fuel maps and cleared the codes, but they came back.

 

[Clayton]

update: I had cleared the codes this morning and when the CEL came back I just assumed it was all three again. Got the scan tool on it just now and after several trips totalling somewhere around 80mi, only p0443 evap emission system purge came back.

I cleared, I'll see if it pops back up tomorrow. Maybe disconnecting the battery didn't clear the stored values and the ECM was confused by the readings from the cleaned MAF throwing things off?

 

[Mark_88]

Hi Clayton,

I'm going to assume this is the 2.5 and that it's a 1999 from where you posted and the year listed in your details.

The evap systems on these vehicles is prone to leaks that can throw codes and if you were recently working under the hood you may have simply knocked a vacuum line off or disturbed something else.

There should be a vacuum line running from the intake to the side fender where you will find the EVAP purge valve. This allows fuel fumes to flow from the tank to the intake to be burned off instead of leaked. If there is any break in that system, which starts at the tank and goes to the charcoal canister near the rad (or other location) and then through the purge valve.

Check the hoses you can see to ensure they are connected properly and not loose. Check also that the gas cap is secured properly according to specs. If you are using a locking gas cap that may be part of the problem so keep that in mind. Do not replace any parts until you can test the system for leaks if you can't find anything obvious.

The P0443 was the code I was getting (I think) and it turned out that I was using a new out of the box locking gas cap that didn't quite seal the system. I put the original cap back on and the code cleared...

Some of the hoses may be worn enough that the ends do not fit snugly on the connections. You can usually snip an inch or so off loose ends and the hose will be able to fit securely...

Someone else with more experience with the Ranger specific problems can probably elaborate better on the code you are getting so if my suggestions don't work...please follow up and let us know.

 

[Clayton]

Ah, that's a huge help.

I haven't got the code back yet, but thanks to your details I have a good idea what caused it. The first two codes were probably from cleaning the sensors and changing the filter, which threw the ECM for a loop until it could adjust.

For the p0443-- I recently changed the fuel pump (it only lasted 6 months and maybe 6k mi...) and I somehow forgot to reconnect the fill neck hoses and drove like that for 20 miles or so. Maybe that has something to do with it, so I'll double check that the hose clamps are secure. Also, while it's not terribly cramped under the hood, I definitely could see having bumped something when swapping out the PS pump which I also did recently. I'll watch for the code again, and next time I'm under the hood check for those vacuum lines and hoses.

Oh, and yeah, this is my 99 2.5l found in my details.

Again, thanks for the tips.