looking to by a 2004 ford fx4 5.4 truck inspection failed die to a downstream 02 sensor code any help

 

i guess that what i am asking is after repalceing how do i reset the code's and is this do to a cat problem or just a truck with 135000 miles on it

 

Is the check engine light on? Do you know the code that caused it to fail inspection? The code is th palce to start. If you don't know the code, you will have to have it checked with a scan tool. If you don't own one most auto parts stores such as Autozone, Advance Auto or O'Reilly's will run a scan free of charge. They can tell you the code or codes that are stored in the computer. Some places even give you a printout with suggested possible causes or repairs.

Erv

 

i guess what i am asking is how bad could it b i don't have the code i have not bought it the guy has been very honest and he said the shop said a downstream o2 sensor all i have and yes the light is o the dash

 

After getting it fixed any auto shop with a code reader should be able to erase the codes which should reset the CEL. As for the rest I am not help there.

 

Dis-connect the battery to reset computer.

 

Oops!!! I missed the part that said you haven't bought the truck yet. I am far from an expert but I have some recent experience dealing with a check engine light being on in my son's car that said all four o2 sensors were involved. It ended up being the ECM (computer) that was bad. The most expensive part of fixing the problem is usually the diagnostics. I would also be asking myself why the fella selling the truck didn't have it repaired before he sold it. It could be as simple as replacing the sensor to a problem in the wiring leading to the sensor or a new computer. I'm not sure if a bad converter would show a code dealing with an o2 sensor. I would still like to know the code and even then I would discount the price of the truck to help handle the cost of the repair to get it to pass inspection. The state I live in (Texas) allows a vehicle to pass inspection with the light on after you prove you spent at least $600 to fix the problem. Also after clearing the code you have to drive the vehicle through what is called a cycle (stop/go and highway driving for a certain amount of time) to make sure the check engine light doesn't come back on. This is usually around 75 miles of driving. I hope this helps.

 

the codes he gave r as follows po325 a p0174 a p0022 he has reduced the price to 6500 from 7500

 

These webpages give the explanation of what these codes mean and the possible causes:

P0325: OBD-II Trouble Code: P0325 Knock Sensor Circuit Malfunction
P0174: OBD-II Trouble Code: P0174 System Too Lean (Bank 2)
P0022: Code P0022 "A" Camshaft Position - Timing Over-Retarded (Bank 2)

This webpage is a list of all obd-II codes: OBD-II Check Engine Light Trouble Codes

From those codes it sounds like there are more problems than just an O2 sensor. Code P0174 does mention that the O2 sensor detected a lean condition. This does not mean the O2 sensor is bad. I couldn't even venture to guess what it will take or cost to clear all of these codes. Therefore I am not sure if the price he is asking is fair or not. Once again I hope this helps.

Erv