I recently bought a 1998 Homda civic Hx the check engine light was on when I purchased it but the previous owner said it was an O2 sensor. So we took it to auto zone and it shot 3 codes.
P1259 which we have no idea what it is.

 

I recently bought a 1998 Homda civic Hx the check engine light was on when I purchased it but the previous owner said it was an O2 sensor. So we took it to auto zone and it shot 3 codes.
P1259 which we have no idea what it is.
P0505 which is my IAC valve
P0140 which is exhaust gas recirculation insufficient flow
I need some help with what to fix first and how to fix it.

 

P1259 is a VTEC code.

Reset the ECU to see whether any return.

Is the HX stock or has there been an engine swap?

 

The engine is completely stock

 

 

I reset the ECU and took it back to autozone and it shot the same codes

 

P1259 - Check whether the engine oil is low and clean the screen in the VTEC solenoid gasket.

P0505 - Clean the IACV.

P0140 - Clean the EGR valve and EGR chamber and passageways in the IM.

 

The idle air control valve is easy to clean and remove. Search, save yourself the $167 they want for a new one

The egr and the egr passage way will need to be cleaned. If you pay $180 for an egr valve you are flushing money down the toilet.

Do not buy a new egr valve, it will not fix the problem. Search civic hx egr passage cleaning on google.

As these cars get older they get more expensive to throw parts at. I picked my car up with a low flow egr code and idle air control valve code and I got a great deal because the owner couldn't afford the $400 in parts and the $200 in labor local shops wanted to charge him so the car could pass inspection. I spent a Saturday afternoon with brake cleaner and got rid of all the codes