Hello All,

I drive an 08' GX470, and today i read codes with my code reader, and to my surprise 9 codes are listed.
P0300- Random Multiple Misfire
P0301- Cyl. 1 misfire
P0303- Cyl. 3 Misfire
P0305- Cyl. 5 Misfire
P0171- Bank 1 System too lean
P0441- EVAP incorrect purge
P0455- EVAP Purge control valve shorted
P0456- EVAP Control Circuit Malfunction
P2238- A/F Sensor Bank 1 short circuited

If anyone could please give me an idea where to start with this thing, it would be much appreciated.

 

Any multiple misfire code is bad news.
Get a compression check on cylinders 1, 3, and 5, and their adjacent cylinders.

Also check for vacuum leaks and low fuel rail pressure and/or bad injectors (clogged? age?)

Chip H.

 

Start by checking fuel pressure. High fuel pressure could mean a clogged fuel line.
replace all 8 spark plugs and try swapping ignition coils. See if misfire codes change to different cylinders.

If it's not the ignition coils and your fuel pressure is normal, send your fuel injectors to be tested for poor spray pattern or clogs.

Try using a strong concentration of fuel system cleaner

Replace o2 sensor and check wiring/connections. If the p2238 code persists it might be a defective ecu. Clean throttle body. Replace or clean maf sensor.

Check for exhaust and vaccum leaks


as for the EVAP related codes, search them up on the internet and look under possible causes/diagnosis underneath each pertinent link.

 

Thank you all for the feedback i will look into all of this over the weekend. The first code i got was for the Bank 1 Sensor 1, which i scanned in the beginning of the week, i scanned it again last night and found the rest of the codes. Now since B1S1 is on the drivers side where cyl. 1,3,5 are, Should i replace that sensor before anything else? If so i located the B1S1 location, and it looks like it is in an awful spot. Does anyone have any tips on how to remove that one, or know a link to a thread where it has been done before?

Thanks Again!

 

I would look at the misfires first. They could be causing it to run rich, which would affect the O2 sensor readings.

Chip H.

 

Thanks Chiph9