Aktech

[QUOTE=forayzor;2599630]Bad wire going to what sensor or actuator to cause both banks lean? He's already replaced almost every part that could cause these codes and a few that wouldn't. Clearly he does not have the knowledge or resources to properly diagnose the issue. I know what can cause an engine to run rich or lean, I've fixed more than you can count. 80-90% of lean codes on this engine is caused by the intake gaskets. This is proven by myself, and proven to be fixed on a large amount of vehicles.

Bad wires or grounds will not cause these codes. The only way to properly diagnose this concern is with your archaic vacuum gauge, or properly with a scan tool, such as Ford's IDS to monitor short and long term fuel trims while at idle and higher RPM. Most effective way is in morning after first startup, monitoring trims and spraying carb cleaner around gaskets. With heat they will swell, hence morning diag time. If gaskets are leaking, you will see short term fuel trims spike negative.[/QUO
Like I said before it could be the gasket. (you should reread sentence) He has not even pulled engine vac yet or tested his drivability vac lines with a plug and hand pump, He sprayed the lines and there was a change in the rpm once. Spraying is a **** pore hit and miss way to test. Does it work? Sure if you hit it, but if you miss it, it does no good. There are a lot of sensors that are fuel related that will cause a lean or rich condition. They all require power and ground to work. A weak ground or bad wire can be a cause of a sensor to not working right. The connection can get dirty and may still work but not good enough. Rust can build up under grounds. The wires and grounds could be working just enough to sent the signal to the computer that it is working. He hasn`t even measured the fuel pressure. Do you think fuel pressure could cause a lean condition? Even fuel regulator may be bad. Does the fuel regulator require vacuum? What if the spark plugs are dirty,ash, oil,carbon deposit, electrodes worn or damage. If the gasket is 80-90% of the time bad tell us what the other 10-20% can be. Give him the elec and/or vac specs on the egr vac regulator solenoid,egr, DPF egr sensor so he can test them. It would be a crying shame to do all that work on the gasket and find out that it was a $1.99 worth of hose that caused the problem. Please reread the first sentence.

13Harleyfan

Another case of who has the bigger tool box, guys, get back on track trying to help this guy. It's obvious he isn't a mechanic so both of you arer going way over his head.

Aktech

Now your your just contradicting your self form the other post/problem about testing. Once again This may be a intermittent problem. Have you ever have a intermittent problem on a vehicle? What if a wire temporarily grounds out while running? What if the is a restriction of flow because of carbon build up? This this another 80-90% common problem? If so what is the other 10-20%?

Aktech

Your right. But most of the stuff can be tested with just a book, volt meter and a hand vac pump. I`ll leave the thread alone now. Hope they can get it fixed. I`m not a mechanic by trade either.

forayzor

The only way to properly diagnose this issue is with the right tools, or he can continue to replace parts. I'm telling how to diag, not a case of tool box size. Don't see you helping either.

forayzor

No contradiction here at all. It is not an intermittent issue, he said the light came on almost immediately. No wire temporarily grounding out can cause a p0401, p0174, or p0171. Restriction of flow is not intermittent, carbon does not build up at times and come loose at others.

Vacuum gauge testing will only show if he has a vacuum leak, and if it's not in hoses that he can pinch off, it will lead to a dead end.

We are telling people to diagnose issues with tools they do not have, only difference is my route will pinpoint the issue.

If they do not have tools to correctly diagnose, and clearly do not want to pay people to diag correctly, the next best thing to do is replace common failed parts.
My statement about testing was sarcastic, clearly lost on you.

You can keep attempting to help while disagreeing with me, I diagnose and fix vehicles all day every day, at a Ford dealer. I would think people would take common trends into consideration to help take shortcuts, but that's just me.

Intake gaskets are not expensive, and are easy to do, same with DPFE sensors.

Marc D

WOW. I thought this was supposed to be a site that helped those of us with limited mechanical/electrical knowledge find solutions to our common truck problems. 50 years ago I was taught in auto shop to look for the simplest solution with the lowest cost to fix the problem. OBD scanners only point you in the right direction. The best way to fix this issue is to have the diagnostic tools that cost thousands of dollars and then KNOW what to do with the information. I appreciate everyone's information but I'll always go with the answers that repeatedly are posted for my solution. This is supposed to be FUN not a pissing contest. U-Tube has some great videos on repairing these codes but ultimately I have to decide where to spend my money.

Taylor13

Wanted to follow up on my P0401 code. After replacing the the PCV elbow hose with a big hole in it, the lean bank 1 & 2 codes disappeared, and I was left with the P0401 (insuffifcient EGR flow). At this point, my engine was idling and running as smooth as brand new, but the P0401 code kept coming back. I finally removed and cleaned the EGR and DPFE sensor. The DPFE sensor did exhibit moderate blockage where the vacuum hoses connected, which I removed with a small drill bit. I reset my code on the 6th, and it has not returned since.

I also performed the repair of the instrument cluster this past weekend to take care of the intermittent odometer coming and going, and my odometer has worked flawlessly since Saturday. This problem started on my 99 F150 in 2002-2003, where the odometer would never stay on long enough for me to get to work, which is about 13 miles one-way

Marc D

Just back from NAPA and they too confirmed the need to replace the intake manifold gaskets. The good news is all the parts are about $110. I figure I'll break another $50 to $75 in parts doing the repair but this is way less expensive than the $900 to $1500 the shops want not to mention the dealer wanting $2300. Book time on the repair is 16 hours. I expect it to take me 3 to 4 days since I'm working alone. (I just put a heater core in and it took two days the book said 10 hours.) With 153K miles on the motor I expect to have to cut all the rubber hoses off as I go but then they should all be replaced anyway. That will tack on another $40 plus anti-freeze $20. OK so $200 is still cheaper.
I'll photo document the entire process post it later.

Franz

I am not a pro but have been working on cars for 30 years. My dad for 50 and we do maintenance and big projects together. We have been baffled with a minor peformance issue with this 4.2 liter engine since replacing the upper and lower intake manifold gaskets and front cover as well. Bought the truck used and not in running condition per the previous owner who had little knowledge of the cause. From the description we suspected and later confirmed head gasket failure. Replaced the above mentioned commonly failing gaskets and also discovered that the connecting rod was bent in the cylinder with water in it.

After all of that we started it up and it ran fairly well for last 4 weeks. Nagging problem was hesitation at initial acceleration (from a stop or very slow roll) accompanied by stalling of the engine about 10% of the time. After lots of internet searching here and elsewhere, replaced DPFE sensor - no change so I took it back, then replaced TPS - no change. No SES light has ever come on, no codes stored. Yesterday, after attempting to clean the MAF (located in large air cleaner canister right?), put the clamp back together and called it a day. While driving home 5 minutes later, the engine stalled while driving ~15-20 mph. Truck would not start in N or P. Can a MAF or IAP sensor failure cause a no start/run condition? If it was one of these, why did it start, run and then fail while driving?

Our suspicion now is that the crankshaft position sensor may have failed. From reading lots of posts, sounds like crank sensor failure leads to no start/run condition, while cam sensor failure leads to very poor running typically. Other ideas - fuel pump failure, fuel filter clogged, no spark - failure of 'coil' sitting atop intake manifold. Help is greatly appreciated - can start another thread if needed.