This Explorer has just over 200,000 miles on it. All required maintenance is up to date and oil changes are always at 3,000 miles. I couldn't locate any kind of leak on the engine, so do I just need to replace the O2 sensors? How many does it have? Which one is bank 1 and bank 2? Are they all hard to get to on this model 02 Explorer? If I can get away with just fixing bank 2, that would be good if it will keep the light from coming on. I just need to get the state inspection next week so I need to get this fixed.

 

I haven't change the O2 sensor on a 2002 V6, so I'll leave those specific questions to someone who has.

As for bank 1 versus bank 2, bank one will be the passenger side for a US car. Standing in front of the open hood, looking at the engine, it will be the bank on your left.

Is the engine idling poorly or running rough under load? It seems unusual that you'd get codes for both bank one and bank 2 at the same time if the issue were bad O2 sensors. I'd expect one to act up independently of the other. You might not want to give up on checking for vacuum leaks just yet, or even a dirty MAF sensor. Are you using a reusable air filter that requires periodic cleaning and re-oiling? If so, I'd definitely start by cleaning the MAF sensor.

But, if your O2 sensors are original after 200k miles, you'll probably see a slight increase in fuel economy by changing them out anyway. However, if you have a misfire you'll be working on damaging those new sensors prematurely. Also if they're original, it doesn't matter where they're mounted, they will be difficult to get out.

-Rod

 

Actually it runs good. No driveability problems at all. I only use OEM Ford air filters and other filters. Does this thing have a legitimate PCV valve that needs to be changed? If so I know I've never changed it. So because there isn't any driveability problems I was thinking it would be the O2 sensors. The codes are for Bank 2 only.

 

are all 3 codes for the same o2 sensor(I think they are). one codes show a lean condition and one code show a rich condition, and one code shows a high voltage condition. if that is for the same sensor that is strange. some people look at changing 02 sensor as maintenance when they get old they start swithcing slowly. my guess is it is the o2 sensor. especially if you do maintenance, clean maf, change air filter, etc. i bought an sng sensor from discountoxygensensor.com the service was great and the o2 sensor worked perfectly. the cost for your bank 2 sensor 1 is $43. that is for the direct fit one. IMHO I would only get the direct fit ones. if you do change them put antiseize on the threads but dont get any on the sensor. you might need a $10 socket

 

you could clean the maf, iacv and check for vacuum leaks. then clear the codes and see if they come back.

* if it was the maf or something else chances are it would have thrown codes for both banks.

 

Oops, yep, I quickly looked down the list and saw "See possible causes for P1130" and immediately assumed 1151 was for Bank 1 and 1152 for Bank 2. If you plan to keep the vehicle for awhile and the O2 sensors have lots 'o miles on them, it won't be a waste of money to change them as long as you don't have issues upstream causing the new ones to get contaminated quickly. If you have a scan tool with datastream functions you could monitor how often they switch from rich to lean to see if they appear to be slow to respond.

-Rod