mikec7909

Normally, fuel delivery problems do not manifest themselves in this manner, but if you think you have a filter issue you can either run fuel pressure and delivery volume tests, or simply replace the filter itself. Usually, this is an intake air leak issue. Intake air leak issue in between the AFM and throttle body? Or broader like Intake manifold leak? I've once sprayed carb cleaner around the engine when it was idling to see for any change, nothing... It could be anywhere in the intake system; a loose connection, crack in a plastic vacuum line, an injector O-ring, vacuum accumulator, etc. You need to do a complete search as these things are often very hard to spot. I just hope it isn't a injector O-ring. Removing and putting back the intake manifold isn't a fun process. -_-

Normally, fuel delivery problems do not manifest themselves in this manner, but if you think you have a filter issue you can either run fuel pressure and delivery volume tests, or simply replace the filter itself. Usually, this is an intake air leak issue. Intake air leak issue in between the AFM and throttle body? Or broader like Intake manifold leak? I've once sprayed carb cleaner around the engine when it was idling to see for any change, nothing...

Hi, I have a 2004 Cayenne V6 which have the same codes, P2177 and P2179 (System too lean off idle bank 1 & System too lean off idle bank 2). It also has 2 more codes: P2191 and P2193 (System too lean at higher load bank 1 & System too lean at higher load bank 2). I've been driving like this for awhile now. Fires up right away on cold starts or warm. Acceleration seems 'sluggish'. When it reaches about 3500 rpm it feels like its being restricted til it hits 4000 rpm and then it lets up and accelerates good. Gas mileage is poor, 11-15mpg. The info display screen reads 8mpg on some days and 12mpg on many others. I've looked and looked for bad vacuum hoses/lines. Especially all the lines along the passenger side of the engine. The sucking / vacuum jet 'hisses', not sure if that's normal. The whole sucking jet pump was replaced about 8 months ago as well as the positive crankcase ventilation. I've taken out the intake hose and inspected it all over for any holes or cracks, nothing. I've cleaned the AFM and eventually just bought a new AFM, which made the Cayenne run amazing for half a day, then it went back to sluggish. I've disconnected the battery for several hours and hooked it back up again on a few occasions to see if it would magically cure the symptoms, nothing. I've changed the air filter with a K&N filter. No change. I've used Chevron with Techron fuel system cleaner on a few occasions, on some fillups it improved performance significantly and goes thru the 3500 rpm hesitation but on other fillups with the cleaner it made no difference at all. :huh: I than decided to check the spark plugs, but when doing so I noticed oil was filled in all the spark plug ports. Which I believe the valve cover spark plug seals all needed to be replaced. So I soaked up all the oil in each port and cleaned each coil. Ordered a new valve cover gasket, 6 new spark plug hole seals, and a new intake manifold gasket (since I had to remove the intake manifold I figured why not). After changing everything out and firing her back up and doing a test drive things felt a little better. No more hesitation at 3500 rpm, but still felt 'slow'. Next day all the symptoms returned. All four codes, the sluggish acceleration, hesitation etc. Things that I may still need to look into are the spark plugs, initially when I took them out they all looked ok at the tips. Just were a bit saturated in oil until I dried them up with a rag. Then look again and again at all the hose/vacuum lines. Could it be possible the issues I'm having is due to a dirty fuel filter? Because like I've mentioned, sometimes a bottle of Chevron fuel system cleaner significantly improves performance, but on other times when I used a bottle it doesn't seem to have done anything. I've read in many issues of the P2177 and P2179 lots of people pointed finger at the fuel pumps going bad. The car always fires up and never stalled on me. It's been like this for several months. Maybe a intermediate issue during idle and high loads? Any suggestions or thoughts would greatly be appreciated. :)