I just bought my 99 F150 sport, 4.2 V6 a couple days ago and i changed the oil and the air filter and now the "check engine light is on." Any ideas on why??

 

Take it to autozone (or some other place that scans for free), have it scanned, WRITE DOWN ALL CODES, come back here and post them, and we will try to help.

Without the codes, you might as well look into a crystal ball.

Make sure you reconnected the sensors around the air filter box. The IAT sensor is easy to unplug and forget.

Steve

 

if the truck is driving perfect. i would make sure the gas cap was on tight and reset my computer. ( unhook one side of your battery and let the lights stay in the on posistion for a fewminutes then reconnect). then see what happens. if it comes back go get it scanned, but i would try that first.

 

Sometimes if you hit a certain mileage the light comes on just to say "hey you hit 40k" or whatever.

 

I was just thinking gas cap!

 

I need help with my engine light please!

I drive a 2002 F-150 and the check engine light is on; I took it to autozone and the result of the test was the following:

Code P0174 = System to lean (bank 2)

Any ideas what this code means???

 

My CEL light came on last summer, at about 70000 miles. No change in performance really. Culprit was the EGR valve, a pretty easy fix.

 

I need help with my engine light please!

I drive a 2002 F-150 and the check engine light is on; I took it to autozone and the result of the test was the following:

Code P0174 = System to lean (bank 2)

Anynk 2)

Any ideas what this code means???

 

Lean means that the ratio of air to fuel is too much air and not enough fuel. Bank 2 is set of 4 cylinders on the drivers side. Lean conditions can be caused by air leaking into the engine (vacuum leaks or pirate air), insufficient fuel pressure or delivery (fuel pump, fuel filter, fuel pressure regulator), clogged injectors, or bad sensors (O2 sensors or mass air flow (MAF) sensor).

Usually if you have a P0174 you eventually get the corresponding P0171 for bank 1. If not, only one sensor is specific to bank 2, the pre-cat O2 sensor. It is the sensor on the driver's side between the exhaust manifold and the catalytic converter.

So many things could be wrong and you could get a P0171 tomorrow. The following works on my truck, and probably on yours. If the O2 sensors are the same, switch the two O2 sensors on the driver's side. There is a small chance that that would fix your problem. If not, or probably anyway, you need a friend that knows about cars or a shop to look at it.

Good luck

 

Before you switch or change anything. P0171/174 are the main codes that tell you there is a vacuum leak. Try this first: at idle, spray starter fluid around all vacuum lines going into the intake manifold. Also spray around thegasket between the manifold and engine. If there is a leak, you will get a surge in idle.

runnert