I need help guys, sorry, just lost at this point
I need help guys, sorry, just lost at this point A couple of weeks ago I started throwing a P0174 code. I did look it up and started by replacing the O2 sensor. Reset the code and a few days later, the same code came back plus one, P0171. So now I'm thinking possibly the MAF, based on my searches on the forum. I've also checked for vaccumm leaks and found none. So, I replaced my MAF with a friends that is working and reset the codes. I drove it for 5 days, 230 miles roughly. It never threw a code while I had my friends MAF on. I returned the MAF and put my old one back on and drove it 65 miles and then the RPM gauge quick working and then the car stalled at 50 MPH. I was able to coast it to a parking lot. I tried restarting it. It would run for a few seconds and stall. I tried restarting several times only to have the same result. Eventually it just quit starting period. So, since the car ran great with my friends MAF, I purchased a new SLP 85MM and installed and am still getting the same results (RPM Gauge still not working). I've disconnected the TPS and the other sensor connected to the TB one at a time and still got the same result. I'm definately at a loss now and am in need of some advice! Thanks for anyone's help who might chime!
Make sure the MAF is clean, use spray cleaner on the elements. From there I would check fuel pressure. You should be able to hear the fuel pump buzz. Is it time to replace the fuel filter? Also make sure there are no exhaust leaks upstream of the o2 sensors. Such a leak could cause the sensor to erroneously report lean. Justs a few thoughts. GL
check fuel pressure as stated above and check youre fuel filter it might be clogged. if by chance you can get the car to start again try and hook up a scan tool and check youre
o2 sensor 1 bank 1 and o2 sensor 2 bank 1, with the car on go for a drive and step on the throttle and look at youre o2 sensor patterns. if youre fuel pump is failing you will see the pattern run flat at the bottom, because youre pump wont be able to keep up with demand. you could also run the smae test with a fuel pressure guage, check pressure at idle and then you can put it in gear and step on the brakes hard and put a load on it and record the pressure drop and compare to specs. hope it helps you out.
o2 sensor 1 bank 1 and o2 sensor 2 bank 1, with the car on go for a drive and step on the throttle and look at youre o2 sensor patterns. if youre fuel pump is failing you will see the pattern run flat at the bottom, because youre pump wont be able to keep up with demand. you could also run the smae test with a fuel pressure guage, check pressure at idle and then you can put it in gear and step on the brakes hard and put a load on it and record the pressure drop and compare to specs. hope it helps you out.
Trending Topics
I also want to add that some times vaccuum leaks can be very small, big enough to affect an engines drivability but not big enough to physicaly see the engine run rough. I know you said youve checked for vacuum leaks already but it wouldnt hurt to double check. once again if you could hook up a scanner and view youre o2s and spray brake cleaner anywhere you think there might be a leak, mainly i would double check pcv lines and see if youre o2 readings change at all while youre spraying.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Check fuel pressure at the schrader valve on the fuel rail. I think AZ, AA, etc... will have one you can use/rent. Take you longer to drive to AZ than hook it up and check it. Drive it easy until you figure it out. Lean = not too good!!
Lean: Not enough fuel in ratio to air OR too much air in ratio to fuel(both are lean). Are you NOT getting enough fuel or are you getting too much air for the amount of fuel being supplied? Is fuel supply a problem(fuel filter, pump, injectors) or is excess air being supplied upstream of the O2s(intake or exhaust leak, broken hose). Eliminate items that effect one Bank only and look for things that are common to BOTH banks. Intake manifold is common to both banks, but the exhaust has 2 manifolds(not common). Fuel filter and pump are common, but injectors are not. Go fish.
I'll be honest, I have no idea of the last time the fuel filter was replaced. I haven't done it and typically I won't let too many other people touch my car. I just never thought about it. So, I guess I can start there. I did a full overhall of the top end last June, so, I hope nothing is wrong there. Plus, it was driven almost a full year without problems. Again, the fuel filter could have well over 100,000 miles on it considering the engine has 163,000 miles.
Change the fuel filter it's in the back near the tank. Then take five minutes and get a fuel pressure guage and check the pressure at the schrader on the fuel rail. Should be at least 59lbs IIRC. Let us know what you have. Many people don't realize a partially plugged filter is tough on th FP and can cut it's life. I change mine every july 4 just to make it a habit.
It looks like you've gotten some good advice so far. Get out there and poke around. You can do it
You should be able to diagnose a fuel pump/fuel filter problem visually. If you don't have a fuel pressure gauge, just find the shrader valve(bicycle tire valve) on the fuel rail and poke it. It should build enough pressure to force fuel out, a brief squirt, even if the car is not running. If very little comes dribling out, you have a fuel delivery problem.
You should be able to diagnose a fuel pump/fuel filter problem visually. If you don't have a fuel pressure gauge, just find the shrader valve(bicycle tire valve) on the fuel rail and poke it. It should build enough pressure to force fuel out, a brief squirt, even if the car is not running. If very little comes dribling out, you have a fuel delivery problem.
I haven't replaced the filter yet, however, I did depressurize the fuel line from the nozzle at the fuel rail. It sprayed like crazy until it quick. Then I turned the key to the on position (did not start the car) and then turned it off. I then re-checked the fuel pressure by pressing the pin and it once again sprayed like crazy. Would this mean that there would be no problem with the fuel filter or pressure?
Alright, so I replaced the fuel filter and so far it is running! 
It tends to be hesitant every now again from a traffic light and in between gears but, it stays running which is key!
Thanks to all that submitted advice, you guys were a huge help!!!
Thanks!
It tends to be hesitant every now again from a traffic light and in between gears but, it stays running which is key!Thanks to all that submitted advice, you guys were a huge help!!!
Thanks!
