I have a 97 Accord EX F22B1. I just recently had to clean out my EGR ports since they were completely clogged. I cleared the CEL that was with that issue and now I keep getting P0171. I replaced the EGR valve gasket & the EGR port cover gasket. The car gets horrible gas mileage (17-18mpg). I sprayed starting fluid all around the gasket areas and didn't get any response out of the engine. The O2 sensors are 14 months old. The only thing outside of cleaning those ports was put on new plugs and install a new PCV valve. I wouldn't think a faulty PCV valve would cause the code. Any ideas? I replaced the injector o rings so they shouldn't be leaking there either. Any help?

Thanks
Rusty

 

hmmm did u clean the whole below EGR?

like stick a hanger wire in like its a pipe cleaner and spray cleaner in there too? and u crank the crank the car for a sec and then kill it.. usually it cleans out there.. or spits it out.. and yea gas milage is off of EGR valve too.. mine was doin the same thats what i did and it helped a while bak but it dont help me now lol.. i dropped like 10 more mils per gallon lol.. cuz of my compression and stage 2 cam...

 

Yeah the EGR is flowing fine now, just the lean condition is my problem. I would guess the CEL is causing the bad gas mileage? I was getting 26-28mpg, now its 17-18mpg.

 

did u check for exhaust leaks

 

What's your engine vacuum at idle?

 

I'll check the vacuum later today or tomorrow. The engine runs smooth so I leary of assuming its an intake leak. I remember there was a small exhaust leak where the exhaust manifold bolts to the down pipe. It wasn't much, I only noticed it when I was sea foaming the engine a while back. I'm going to pull the plugs and see if they are white as well. As well as test the fuel pressure.

The bad gas mileage but yet its lean confuses me a little.

 

How/Where do you connect a fuel pressure test gauge? I can't find a schrader valve or test port anywhere. The only way I see is that you would have remove the cap where the fuel line attaches to the rail, however none of the fuel pressure test kits I've seen have an adapter.


Also just noticed that if I pull the PCV valve or oil cap there is an ton of air blowing out. I know that there will be some air but this seems excessive almost.

 

EGR valve is working fine,I put a vac pump on it and it killed the engine. There isn't any vac leak that I can find, I used about half a can of starting fluid.

 

Did you use OEM oxygen sensors? I've encountered some aftermarket sensors that were faulty.

You should be able to use a multimeter or graphing meter ( prefered ) and watch the response of the primary oxygen sensor to creating a vacuum leak or injecting some propane into the intake air stream. It's possible to have a biased oxygen sensor giving a false condition and poor gas mileage.

 

That's one of the things ive narrowed down to, either O2 sensor or a bad fpr. I can't find an adapter or port to hook a fuel pressure gauge up to so I can't check the fpr at the moment.

 

In all my years I have never had to replace a fuel pressure regulator on a honda.

 

What about the purge control valve? I took it to a Honda shop (not dealership) and they said the purge control valve is working intermittently. They can't find any other problem but said to try this but no gaurantees it would work. Any thoughts?

 

Has your P1457 monitor run and passed? A failed purge valve would eventually set a P1457 ( EVAP leak/malfunction ). If the purge valve doesn't open when the ECM commands it a lean condition can occur. The ECM compensates fuel trims due to the extra HC molecules entering the intake through the EVAP purge valve. I doubt it though if your P1457 has run and passed.

How do they know the vavle is working intermittently? That, I would like to know.

 

The mechanic said that you can hear (w/ mech scope) or feel when it opens and closes. He said he tapped it and it started working again. Personally I'm not too knowledge on how the valve works. I havent had the P1457 code yet. My only thought on how it could be a problem is if its stuck open its pulling too much air and causing a lean code and the ECM is dumping more fuel. I guess a test would be to plug that vac port and try that?

The stealership wants $170 for the part, but I found out that any 94-97 valve from a 2.2L will work so I'm going to run to pull a part this week and save some $$.

 

The last thing you need is the advice of someone who works at a stealership. Good luck.

 

The advice came from a mech shop that specializes in Hondas. The price for the part came from the dealership, I can't find any other parts store that carries one.

 

My CEL is back on and the purge solenoid was "clicking" when I got to work. If I read my manual correctly, the solenoid is only powered when the car is at operating temperature. I haven't checked for vac at the solenoid yet, but I plan on running to the junk yard today to pick up one to test it out.

 

I bought a scan tool and scanned the CEL and came up with 3 codes, P 0170, P0171, & P0131.

The freeze frame data from the P 0171 is:
Fuel Sys 1 CL
Calc Load 27.8
ECT 188
STFT 39.8%
LTFT 19.5%
Map 8.2 HG
RPM 1262
IAT 120 deg
TPS 9.4%


I have the ability to read live data. Can anyone help?

 

Excessive EGR flow could cause a lean condition.
Based on your freeze frame data your fuel trim is way off,
I would say you should go
back and make sure you didn't leave any hoses off during
your EGR repair.
Another good way to check for a lean condition, and eliminate
the possiblity of leaks is to use a smoke machine.

The p0131 points to your primary 02 sensor, and or
the circuit involved with it.
I would check for adequate voltage to the primary o2 sensor,
and the proper resistance.
Although excessive fuel pressure could cause this code too.

My initial thoughts are that if you didn't have the p0131 before
your repair, then your probably caused it and t's probably
a by-product of your real problem.


Good luck.

 

The EGR works properly. I can hook a vac pump and apply vacuum and it will kill the engine. Me nor a shop could find any vac leaks. I've tried starting fluid and propane. The short and long term fuel trims being high would explain the excessive gas consumption.

The shop I went to said to replace the purge valve and that it wasn't working however I think they are wrong. I tried a junk yard purge valve and it works the same as the one on my car. I think ( I could be wrong) that it only gets power from the ECM when the engine is warmed up and when the outside air is warm. Ive noticed that when I drive it in the morning and its cool out it wont come on, however when I drive at lunch or in the afternoon it works. I never have a multimeter on me when its not clicking but i'll try this weekend.

Do they make any cheap smoke machines?

 

I took a long drive up the interstate today and had my scanner plugged in. The primary O2 sensor read 0 volts for 80-90% of the time. When I was in sitting and go traffic it would occassionally move but very rare. The secondary O2 sensor read .895 volts 90% of the trip.

 

Try this to eliminate the O2 sensor...

Clear the codes then warm the vehicle up to operating temperature.
Then with your scan tool on live data watch the primary o2 sensor
voltage reading at wide open throttle.

The concensus is that if the voltage does NOT stay at 0.1volts or less
then your problem is intermittent and you should check for loose wires
between the primary sensor connector and the PCM connector.

If the voltage is 0.1volts or less, then your condition is live and you should
check for proper fuel pressure. Checking the fuel pressure will tell you if the
sensor voltage being low is a result of excessive fuel, or if the sensor it self
is malfunctioning.

If the fuel pressure is out of spec, find and repair the problem
If the fuel pressure is in spec, then go back to testing the o2 sensor.

Turn vehicle off, then disconnect the primary o2 sensor.
Start the car and check the output voltage of the sensor
while it is running. If the sensor voltage does NOT stay at 0.1volts or less
then it is garbage. If it does stay at 0.1 volts then turn the car off.

Disconnect the PCM connector. Measure the resistance between ground
and the Primary o2 sensor connector . (White/Red wire)
If continuity exist, then you have a short to ground in the wire between
the PCM connector and the primary o2 sensor.
If there is no continuity replace PCM.

 

I finally took it to the dealership and they can't figure out what's wrong. The fuel pressure is good. No intake leaks. The guy said it could be a bad injector(s) and would start by replacing them. One would think that a bad injector would cause a mis in the engine or at least that's my experience with bad injectors or injectors with a bad spray pattern.

 

What did each one of your spark plugs look like when you pulled them?

A low fuel flow issue in one cylinder does not always create an audible miss. The fact that your ECU threw code P0171 "fuel system too lean" points to a few possible things;

• Fuel Supply (suspect the injectors if your fuel pressure is good)
• Primary O2 sensor
• Improper Valve Clearance
• Exhaust leak
• Contaminated Gas

& the DTC P0131 "Primary HO2S circuit low voltage", is the second code that points toward a faulty PHO2S.

 

Fuel Supply is good (42psi)
Both O2 sensors (Bosch) are 14 months old
I only pulled a couple of spark plugs so I need to pull the other two to make sure, but the ones I pulled were black (running very rich).
It's not a fuel contamination issue because I've gone through a dozen or more tanks and different gas stations.

It's something out of the norm. My LTFT is around 20% and mileage has dropped by about 10-12mpg so something its either has a false lean or something else. It would take an extreme exhaust leak or vac leak to throw it off that bad I would think.