I have a 2007 Honda Accord EX 4cyl. and I'm getting a DTC P0171.

1. I have checked for any exhaust & vacuum leaks-none
2. Checked for any oily residue on MAF-none seen-still cleaned with electrical parts cleaner
3. Car stumbles on acceleration-won't go past 60mph
4. What should be the fuel pressure at the fuel rail be? Would a clogged fuel strainer on the main fuel pump in the tank cause this problem?

 

Fuel pressure is first thing in diagnostic tree is to check fuel pressure. Measuring fuel pressure on this model appears to be difficult requiring a special hose assy w/ tee to replace the stock jumper from fuel line to injector rail. I ran into this problem w/ 01 Celica. You can make your own adapter, but a spare fuel jumper will be required (junk yard part). Fuel pressure spec from 03-06 manual was 47-54 psi.

P0171 can be either unmetered air (leak somewhere) too much air, or a blocked injector (too little fuel). I had this problem (persistent P0171) w/ 01 Celica and had to have a injector balance diagnostic performed by a local shop to find the problem. This test takes a special tool to energize each injector w/ pulses for a fixed time period and measure how much pressure drop. Even a few psi difference between injectors will cause problems. I did all the air leak investigations including several smoke tests and verified no intake air leaks, before I had the diagnostic revealing partiallly blocked injector. See youtube for videos on subject.

If you plan to diy, you should get the shop manual (automanualsource.com) for $22.

good luck

 

Hey Texas,

Thanks for your feedback.....I appreciate it