Still getting codes p0327,p0174, and p0171. But I have noticeed that the o2 sensors after the cat. rattle when I give it gas. Could this rattle cause me to get code p0327 cause it may be detecting it as a knock?

Still getting codes p0327,p0174, and p0171. But I have noticeed that the o2 sensors after the cat. rattle when I give it gas. Could this rattle cause me to get code p0327 cause it may be detecting it as a knock?

your engine is running lean ..the ks will act up if this is the case as you will get increased engine noises with a lean condition...since both O2 sensors are saying the fuel is insuffiecent for proper operation you must check for vacuum leaks, any air leaks after the maf sensor...throttle body gasket,intake manifold....

the other possibility is the fuel delievery is insuffiecent,,,check fuel pressures attach a long hose and monitor fuel pressures while driving, replace and cut open fuel filter to see if your tank has been contaminated...

I was wondering if I may have a bad Idle Air Control Valve?

Always diagnose and repair the first DTC (in the order they are retrieved), first. Any DTC's after the first one can be set as a result of the first DTC. In your case, a problem in the Knock Sensor or circuit can trigger the P0174 and P0171 (lean) DTC's.

P0327 "Knock Sensor 1 Circuit Low Input Bank 1". Diagnose the KS circuits and KS first:

KS disconnected, check resistance between the KS lead wire and ground, should be approximately 100 ohms.
KS disconnected, ignition in the ON position, engine not running, KS vehicle harness connector should show 5VDC.

Post your results.

I drove back fro the Livingston area to Houston area with the engine light off. Drove there with it on didn't drive the truck for 2 days, but when I started it the light was off. I drove for at least 120 miles with the light off. Im getting good gas mileage so that makes me think I dont have a vacuum leak or a fuel problem. Cause 230 miles with just a hare under 3/4 of a tank (one line just to the left of the 1/4 tank mark). Thats why I am stumped.

I drove back fro the Livingston area to Houston area with the engine light off. Drove there with it on didn't drive the truck for 2 days, but when I started it the light was off. I drove for at least 120 miles with the light off. Im getting good gas mileage so that makes me think I dont have a vacuum leak or a fuel problem. Cause 230 miles with just a hare under 3/4 of a tank (one line just to the left of the 1/4 tank mark). Thats why I am stumped.

If you take the time to review the posts here you will find many a fuel pump has been erradic in pressures supplied..

I have noticed something else since I added Lucas Octane booster 200 miles ago the engine light hasn't come on. Is this normal?

I have noticed something else since I added Lucas Octane booster 200 miles ago the engine light hasn't come on. Is this normal?

with the higher octane the engine is not going to detonate as much.
so with that, It still needs fuel and other tests to determine why its running lean..

Well from my last topic I drove another 80 miles and then my light came back on again.

I was waiting for that, additives rarely help. Look at Old Master's post.

Just had my truck scanned again an here are the codes in order P0122, P0171, P0327. Now what do I do?

Just had my truck scanned again an here are the codes in order P0122, P0171, P0327. Now what do I do?

the dtc 122 is the TPS. this is because this throttle position sensor is sending a voltage lower than .25 volts... the computer expects .5volts or higher. at WOT the voltage should be about 4.5volts..

check for bad wires, connector then replace TPS...if necessary..

I have noticed something else since I added Lucas Octane booster 200 miles ago the engine light hasn't come on. Is this normal?


Detonation ocurs when the air/fuel mixture is completely burned before the piston reaches top dead center. Vehicles with adjustable distributors allowed you to advance ignition timing to accomodate for the slower burning, higher octane fuel.

The PCM is programed, and the distributor is oriented so that the engine will operate properly with 87 octane fuel. If any detonation is detected by the Knock Sensor, the PCM will retard ignition timing until detonation is no longer detected. Use of octane boosters and higher octane fuel is not necessary and will not improve performance or fuel mileage.

Detonation ocurs when the air/fuel mixture is completely burned before the piston reaches top dead center. Vehicles with adjustable distributors allowed you to advance ignition timing to accomodate for the slower burning, higher octane fuel.

The PCM is programed, and the distributor is oriented so that the engine will operate properly with 87 octane fuel. If any detonation is detected by the Knock Sensor, the PCM will retard ignition timing until detonation is no longer detected. Use of octane boosters and higher octane fuel is not necessary and will not improve performance or fuel mileage.

old master
this guy has had these issues of detonation since the engine was rebuilt.this goes back to his earlier posts months ago, and he at that time said he had NO money to get the diagnostics done to fully check out the sensor operation...he needs a fully functional scan machine ...

the TPS code is a new dtc ....