Last year it died and rough idle at stop lights, but I changed the purge valve selonoid and it helped for 6 months and then again, now I'm getting p0150 whcih is 02 bank 2 sensor 1.

Local shop told me to take it to Ford for a pcm update of parameters. Truck always had a rough idle, now gas mileage went bad.
What do you guys advise?

 

Potential causes

Water or corrosion in the connector
Loose terminals in the connector
Wiring burnt on exhaust components
Open or short in the wiring due to rubbing on engine components
Holes in exhaust allowing unmetered oxygen into exhaust system
Unmetered vacuum leak at the engine
Bad o2 sensor
Bad PCM

Read more at: https://www.obd-codes.com/p0150
Copyright OBD-Codes.com

 

I appreciate you helping! What do you recommend I do? Basically local shop suggested pcm upgrade first and then said change 02 sensor.

 

Is your 4.6 a 2 valve or 3 valve?

 

4.6. 2v. Light just came on again today p0150

 

Pfft! Sounds like a stealership. they want to start with the most expensive and least-likely-to-have-failed-part first! Most of the things that Roadie named can be checked visually. Get under the hood, under truck and under the dash and check them. If you can't find a problem there, then replace the O2 sensor and only change the PCM if all else fails.

Then go find an honest repair shop.

"Local shop told me to take it to Ford for a pcm update of parameters."

More incompetent advice. Your truck should run fine with the original PCM parameters, as long as it doesn't have other problems. The fact that anyone would suggest an "update" without a good reason says that they have no idea what they're doing. Find the problem and fix it. Only after everything is working as it's intended should you even think about an update. And frankly, I wouldn't update unless the dealer can give you a dammed good reason and that they'll guarantee that they will return it to it's original parameters if the "update" doesn't improve things.

 

I agree with the way you think. Light went off again. In the past 2 years every 5 months I would replace the purge valve selonoid and the stalling would stop.
But that doesn't *fix* it anymore.

Local shop ran codes and didn't find it, but looked at each O2 sensor and looked at the voltages, also checked for intake manifold leak and didn't find any.

They checked only and saw Ford issues a TSB, saying that if updated it should fix the issue, local shop said to go to dealership for update and if that doesn't fix it, they said a smoke test and a O2 replacement would be next.

I don't know how to check the parts or where to even look. Any ideas? Please help guide me, I'm desperate and scared about hundreds and hundreds of dollars and not getting anywhere

 

Why not just change the 02 sensor.

I replace them on all my vehicles at around 60-80k miles. They are consumable items in my mind...

 

Ok, I will and will report back

 

Mauual's suggestion is worth a try. O2 sensor's aren't hard to change. Otherwise follow Roadie's list. I've never had to change an O2 sensor in any of the Fords that I've had so I can't be certain but I don't think that a faulty 02 sensor will show good, then bad, then good, then bad, etc. I have found bad O2 sensors in other brand vehicles and when they fail, they FAIL, period. IMO you probably have a sensor wire that is randomly shorting out or is developing an open circuit. (I'll go ahead and insert this here, I've had HUGE amounts of trouble with mechanics that don't give a damm about other people's vehicles and that YANK the connectors apart and break them and a few months later the connectors start failing and all kinds of random problems appear.) Yeah replacing that $1200 module does fix the problem but only because it also replaced the connector. I've troubleshot a lot of hairy electrical problems and I've actually only found ONE bad emissions control module (and some bad O2 sensors but those are usually easy to find), everything else had been due to wiring faults and usually due to something that some ham fisted mechanic either broke or misrouted and it got burned or rubbed on something and damaged the wiring. Start at the sensor(s) and check the wiring all the way back to the computer. Unplug any connectors and take a close look at them for corrosion. If you don't have one, I strongly recommend that you get an electrical service manual. It will show the routing of the wires and the location of all of the sensor, connectors, etc. I would also suggest getting a can of electric contact cleaner and give them all a good blast while they're apart.

I don't know if a failed purge valve would cause an unmetered vacuum leak but I think it's possible. Somebody with more experience with that can probably tell you. But it's very possible that your "new" purge value has failed. However I THINK that if it had then you would getting errors from both O2 sensors.

Have you checked the exhaust system and made sure that there are no holes in it? No cracks in the exhaust manifold, etc.

"Local shop ran codes and didn't find it"

???? Had you already cleared them?

What code(s) were you getting before you changed the purge valve. How many miles do you have on that truck and have you ever changed the plugs or coil paks? It's difficult to say if your rough idle is related to the P0150 code, particularly if it's been going on for a long time.

 

Once again, thank you Joe and everyone in this thread!

Miles at 101k, purge valve changed since 50k and every 10/13k miles. As soon as the truck would start stalling at stop signs ect I would change the purge valve out. (this time changing it out didn't *fix*issues.

Quality coil packs and plugs were changed at 67k, also replaced the charcoal canister just because i thought it would help (at the time I was searching problems about why the purge valve selonoid keeps going dead and I was recommended to replace this charcoal canister.

I guess not I'll change this 02,qnd I'll have the shop check wiring and look for vacuum leaks and exhaust faults and report back.

But the rough idle has been there since I bought the truck at 43k, it has started to idle slightly rougher!
This P0150 (bank 2 sensor 1) code is rather new, only on and off in the past 2 months (say 8 gas tanks), it doesn't stay on, but it doesn't turn off on any pattern either. It's random, at times it's on for hours and others a week or so.

I wonder if it's just the Evap system at fault somewhere. But how can a mechanic find that out.

I love this truck. It's stressing me out this problem. But I love my Ford f150, I love it

 

FWIW i have a 2010 but with the 5.4. I've never changed the plugs, coil paks or purge valve and it's still running fine at about 96k (Knock on wood!). I don't know if your problems are characteristic of the 4.6 or not but it sounds like there's something wrong in your's that no one has figured out yet.

"Miles at 101k, purge valve changed since 50k and every 10/13k miles."

I caught that in your earlier message that you had changed the purge valve several times and I'm wondering what's going on there. I think there are ways of manually testing the purge valves, if I were you I would check any that you take off and see if they are actually bad. You shouldn't have to be replacing them like that.

"replaced the charcoal canister just because i thought it would help"

I really recommend that you don't change parts unless you're pretty certain that they're bad. I've seen too many bad new parts and installing a part that creates a second problem in addition to the original problem will just confuse the hell out of troubleshooting! Sometimes you don't have any real choice but to change parts and to see if it fixes the problem but it's best to avoid doing that unless you don't have another choice.

"I wonder if it's just the Evap system at fault somewhere."

I THINK the built in test would probably catch that. But I think you can probably test it for leaks using a hand pump and a gauge like this one <https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html>. This may not be large enough and I don't know the acceptable limits are. You can also probably check the purge valve operation by applying DC power to it. The Ford Emissions Control System Service Manual should tell how to check it, or you may find it on the internet somewhere.

 

PS

"This P0150 (bank 2 sensor 1) code is rather new, only on and off in the past 2 months (say 8 gas tanks), it doesn't stay on, but it doesn't turn off on any pattern either. It's random, at times it's on for hours and others a week or so."

I can't tell you for certain on the F-150 but on the last car that I had to troubleshoot was very finicky about setting and clearing the codes for a lot of the emissions system. It had to go through THREE cycles that included warming the engine to a certain temperature and then driving a minimum of (IIRC) 45 miles at at least 40 MPH and some other requirements before it would set a code for a bad O2 sensor. In town driving wasn't enough meet the requirements so the only time that it gave an O2 sensor failure was on the occasional weekend when I drove out of town.

Some of these car computers are getting TOO clever IMO.

 

Thanks again, I started changing the purge valve selonoid as I've read online that it helps my stalling and rough idle problems. (it always did help the stalling, but never the rough idle) I simply changed it because when I did the frequent stalling at lights immediately stopped, I'll test the purge valve selonoid and find out