chech engine
#1
chech engine
Hi All:
I have a 97 expedition 4.6l with codes PO174 saying bank 2 was too lean, a failed HO2S21, whatever that is. Also check engine lite is on that is why I took it to autozone. The engine runs smooth at idle and high speed. I am going to check the maf but that should make the whole lean. Any idea? 100,000 miles on truck
Thank in advance
john
I have a 97 expedition 4.6l with codes PO174 saying bank 2 was too lean, a failed HO2S21, whatever that is. Also check engine lite is on that is why I took it to autozone. The engine runs smooth at idle and high speed. I am going to check the maf but that should make the whole lean. Any idea? 100,000 miles on truck
Thank in advance
john
Last edited by dustmop45; 03-23-2008 at 05:35 PM. Reason: adding
#2
No Pain, No Pain!
Welcome to the board!
Could just be a bad O2 sensor on bank 2. There are some great mechanics here, so they will be better able to give you some suggestions.
Could just be a bad O2 sensor on bank 2. There are some great mechanics here, so they will be better able to give you some suggestions.
#5
Resident A-hole
Bank 2 lean could be a vacuum leak or a bad injector or an exhaust leak or a bad o2 sensor. If you have over 100k on the truck replace the o2 sensors. Check the vacuum and breather hoses to make sure there is no leaks.
#7
Senior Member
Welcome to the forum! I get the same code on my 02 4.2 V6. If you have access to one of the tool trucks that depend on their living from the techs at the dealerships, ask him to check with the pros. I was informed it is the intake gaskets that are the problem. Especially if the code is printed on cold morning starts. My truck also runs like a top with no other codes or symptoms. 166k on the odometer. Good luck! I'm still trying to verify the condition so I can do a before and after test. Here in Las Vegas it will be December before its cold enough to throw a code.