My check engine light came on last night and has stayed on since. I read my manual and it says it could be a bad tank of fuel, loose gas cap, or emissions control device malfunction.

I'm guessing that means my 0xygen Sensor or EGR valve is shot.

Is there a way to read the trouble codes without a scan tool?
If I need a scan tool, how would I use it?
Is the Oxygen Sensor easy to replace?
Will I need to reset the indicator light after replacing the part?

Thanks,
Eric

 

Go to auto zone and have them read the code. Get the number and post it here and somebody will be able to help you out.

 

Whoa, whoa, whoa....

Stop with the guesses here. You're acting just like my folks tonight--freaking out over nothing. (I had to shut down the plant tonight and they freak like the storm is on my doorstep now...)

1. Assume nothing. Even the loose gas cap.
2. Not on anything after 1994 models. Other than maybe Heavy Duty trucks with the OBD1 still in them after 1994.
3. Buy scanner, read instructions. Couldn't resist. OBD2 is generic, federally mandated. Pretty much the same between all makes.
4. Ask when it comes time to replace an O2 sensor. IF it is dirty, replace it. It is RARELY the actual problem these days. Think about that and why that is the case. I have explained that in the Ranger forum, if not here, before.
5. See #3. Or my favorite, pull the fuse to the computer only in that underhood fuse box. Keep radio presets and less hassle than batery cables.

 

Hold on. Blueoval has a concern. Not enough info yet for us to help but that doesn't mean he doesn't have a problem. Oh I do like the suggestion to pull he PCM relay and keep my radio presets. I'll have to check the schematic again and see if KAM is run through the relay. Otherwise, the codes and correction factors will remain.

Back to the original concern, I assume the assumptions made on EGR or O2 has to due with the generic hype about check engine lights. Back in he 80's when O2's first came on seen, this was the generic response to a CEL - must be time to change O2. In fact many manufactures had a time or mileage driven trigger that lite up an actual "change O2" light on the dash. So I can understand an assumption right off the bat like this. Particulary if the post knows he has never changed any of these devices.

But of course I wouldn't diagnosis off such an assumption. O2's do remain to be high on the parteto for fixing EFI control systems. They are one of the 3-4 major inputs to EFI control. Always have been and continue to be today.

So yes first we need the codes. Looks like you truck is 1998 per your profile so this is in fact OBDII. OBDII was fed mandate from 1996 model year on. Some Fords had OBDII in 1994 and 1995 as test pilots. While the majority of the codes are a federal mandated standard, they left a few strigns open here and there for the manufactures to expand their outputs for some particular needs. And these can even vary from model to model. Different scanners are capable of reading different codes. They all read the Fed ones but you may need to pay for upgrades to read Ford, Chrysler... specific codes. I opted to not get the Dodge codes for my Durango at this time since it's a 2002 and I don't expect any issue beyond what the Fed codes will cover. To date it has never thrown a code.

Either way you go get your own scanner or have it read by someone else, the codes tell us why you get a CEL, then we can go from there.