98mustanggt28144

OK when i'm taking off or i down shift and run my RPMs up too 5000 or 6000 my car will sound like it has bent the valves or a rod is knocking and it loses alot of power!! i can stop getting on it for a 1/2 mile or so and it clears up!! but if i don't get on it at all and drive it normal it ALWAYS has power and doesn't have any knocking noises at all!! whats the deal here?? It also has good take off up until 3000 then it don't build rpms fast then at 4000 and up it really runs!!! the only trouble code its giving me is P0131 Upstream Heated Oxygen Sensor circuit out of range - Bank No. 1.
please help me guys!! Thanks in advance john

Repzard

Hmmm good question.
My guess, to much crank shaft play or timing chain slapping?
Could you get any sound clips?
May help better answer your question.


GL

my 2

98mustanggt28144

yea ill try too get a sound clip for u guys.. but i noticed today if i start out in first gear and run it like in racing someone is when it does it (4000 to 5000rpms) is where i shifted today and it done it agian!!!! it starts spittin and sputterin and has no freakin power but i can pull over and turn the car off and let it rest for a few mins and crank it back up and it straightens itself out!!! i did change 1 thing i went back to factory crankshaft position sensor setup and took the steeda setup off but it never done that with the steeda setup could this be the problem?? its like its running out of gas is how it sounds and i hear a lil knocking noise on the back passenger side but if i drive it like a normal person (hard to do with the new hp gains) it runs and drives like new and never has the knocking noise

98mustanggt28144

OK i just left my house and did a burn out and it did it so i hurried up and hooKed up my code reader and heres the codes it gave me #1.P0155 Upstream Heated Oxygen Sensor circuit fault - Bank No. 2. #2.P0171 System Too Lean - Bank No. 1. #3.P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2.

98mustanggt28144

how can i fix these codes and are they my problem??

redneck racer

This sounds like your issue, and is probably causing the other 2 issues aswell. Try cleaning the MAF and all of the intake stuff. MAF cleaner is cheap and you will be suprised how much crap you can clean out of there if you havent done it in a while.

Symptoms: You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.



A code P0171 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor.
Possible SolutionsPossible solutions include:

In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper fuel pressure

98mustanggt28144

ok ill clean that because when i did my clutch i had to run up too a auto parts store to rent a slide hammer to get my pilot bearing out and it rained on the motor for about 30 mins and i have a k&n oiled air filter and i also noticed a vacuum line that runs to the back of my plenum smashes itself completely shut when i rev the motor so im gonna replace it too!! but i also noticed under the car all of one of my oxygen sensors wires are ripped in half (driverside closes to the motor) so im gonna fix that too if anyone else has any ideas let me know thanks

98mustanggt28144

also i noticed today that all my s/p wires "SNAP ON" when i plug them up on the sparK plug but the 3rd s/p wire on the driverside will go all the way into the hole!!! i dont get any snap feeling or nothin can this be part of my problem also?? its liKe its not getting good connection???

98mustanggt28144

come on guys i need yalls HELP!!

TRUEBLUE3934

Yes, fix the O2 sensor wiring. I can't believe it doesn't throw a code for that!
Remove the #3 wire and squeeze the inside terminal so that it will fit tightly over the plug tip.
Get some MAF cleaner and spray it down REAL GOOD! Be very careful not to "scrub" the small wire harshly or you will ruin it.
If it hasn't been changed lately, it would be a good idea to replace the fuel filter. Although I don't think that is the root of your problem, it can restrict fuel flow and cause problems when you exceed the fuel demand it can flow.

Let us know your status after completing those items.
GOOD LUCK!