Problem Description and Possible Solution
The Check Engine Light may illuminate with fault code P0171 and/or P0174 stored, indicating a lean fuel mixture. Our technicians tell us the left valve cover gasket, upper intake gaskets, vacuum line, and bolts may need to be replaced with updated parts to correct this concern.
Average mileage: 121,314 (15,000–243,000)
Engines affected: 3.0L V6, 3.8L V6
88 people reported this problem
I had the p0171 code so I replaced the pcv valve I removed the check engine light. Now I have recieved the p0174 light? I hear a hiss like a leak but cant fine it. I sprayed carburator cleaner to see if the idle changes but didnt notice any change. Also there is some kind of hesitation on take off? What can it be?
leak in the vaccume, causing car to rev and jump when idoling. have to have constant pressure on the gas when idoling to stop van from jumping in place or dying.
I currently have this issue, need to repair. Any suggestions?
Code P0171 and P0174. Cyl 1 and 4 lean. Check engine light comes on and will stay off 24-36 hours when I turn it off. Is this caused by vacuum leak somewhere?
Check engine light, lean codes. Purchased intake gasket kit from Advance Auto Parts. Had purchase new intake isolator bolts online, as ford has changed the design. Also replaced spark plugs and wires, as its easier to reach the plugs on the back side with the intake off. Replaced upper radiator hose because had to disconnect from lower air intake. Total cost of parts was approximately $230.00.
Codes P0171 & P0174- engine runs lean, check engine light is on. Diagnosed at dealer wants $950.00. I am getting other estimates
I had this same problem. Seemed like a power drop and the engine light would come on. My mechanic said the is a know FORD problem with the intake and there actually a Intake manifold kit to fix the problem. Of coarse Ford will not step up and fix the problem. The repair Cost $800 but has run great ever since. Another poor Ford design.
got codes p0171 and p0174 so we changed the o2 sensors all 4 after that started it up ran for a little then acted like it was choking and died got another code p0134 changed that sensor again still does the same damn thing starts up then dies the more times we start it the faster it dies and runs our battery dead..
My van will idle high....in gear at a stop can be close to 1700 rpm. Put it in park and we have gotten a 2200 rpm out of it. It is an intermittent problem. Sometimes if I turn off the van and restart it, the idle will be normal again.
MIL on with codes 0171 and 0174 dies once in a while
engine light is on an van runs like crap
Both banks running lean.They changed the intake manifold gaskets and 6 months later the same BS. They tightened all the bolts and that lasted 3 weeks.Last week they said the fuel pressure was low (22PSI) so the fuel pump and all the filters were changed.Three days later another check engine light.They said it was because of the cold weather and if you let it set in idle for two long when you are letting the engine warm up it would cause the check engine light would come on. Now I was told it won't matter and the manifolds would have to be pulled and they would silicone the gaskets so it doesn't leak anymore. I was also told that I could drive the van for 20,000 miles with no problems. They would split the repair with me but not until the weather warms up.
Ford dealer says the plenum gaskets are leaking. I will try to replace them and see if this solves the issue.
I have had the codes that aay bank 1 and bank 2 running lean it dies at idle it cuts out on acceleration at times I have done tune ups had the fuel filter changed had the fuel injection tested had vacuum leak check changed and reprogrammed the main computer was being told it could possibly be o2 sensors or catalytic converter im stumped because they can't seem to figure out the exact problem and I don't have the money to keep spending while we try to figure it out
I HAVE HAD THIS PROBLEM FOR YEARS AND EVERY TIME I BRING TO DEALER OR LOCAL MECHANIC THEY NEVER FIND CODES THEY JUST CLEAR LITE AND IT STAYS OF FOR MAYBE 1-2 WEEKS THEN BACK ON
Upper Knocking, codes PO 171,174 high fuel consumption
The Check Engine Light may illuminate with fault P0171 and P0174, my engine is 3.0L, only find repair kits for engine 3.8L, why?
we are still trying to get it fixed
Still have not had it fixed, mechanic did a smoke test and named intake issue, they said it would cost $1200 to fix. Asked the mechanic who put the engine in to check it out and he said he heard nothing and cleared the codes. Bringing it back in this week to see if we can begin work on it.