Replaced battery and now CEL

Several days ago I noticed my battery was really weak when starting the engine, so I took it out and put on the back of my other truck, then swapped it for a new one at Walmart. I got the new battery home and put it in the Taco yesterday, and then today after driving about 40 miles I notice the CEL. I pulled in Advance and had it scanned, and it came up "ABS low voltage" (I assume from the former weak battery), and also P2241 "Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)". The guy cleared the P2241 code and I drove about 30 miles and it came on again.

It's odd how I never had a CEL until I changed the battery. The new one is an EverStart 24F with 750CCA so it should be strong enough. Anybody else ever get this P2241 code?

 

Maybe you have an alternator failure and there was nothing wrong with your old battery. Have you checked your charging voltage?

 

I haven't, but I drove about 110 miles today with the ac and radio going the whole time, also wipers and headlights were on for about 40 miles. Still starts strong.

 

That's weird lol

 

Sounds like you have a short somewhere in the heater circuit for B2S1. It could be the sensor itself, or somewhere in the wiring/relays in the circuit. See if the online PDF manual has a troubleshooting flowchart (likely does) and follow it to the letter. Before that, though, I'd doublecheck terminal connections, ground connections, etc - the obvious 'easy' stuff. Then dive into the weeds.

That said, I have gotten some weird pending (no light) codes on my '14 - P219A and P219B - codes which would suggest badness in the head(s) and $$$ to fix. Cleared them and nothing has come back. They showed up on a really taxing trip up to 10,000 feet from sea level, in a LOT of heat, nasty mountain roads, etc. I know my battery is probably close to meeting its maker, and I think these trucks are WAY more picky about voltage sags and spikes than my '04 ever was. That's just my uneducated theory, at least.

 

Double check all your battery connections and if push comes to shove take the battery back to where you got it and have them put a load test on it as crazy as it sounds back when I used to work at Napa we would occasionally have a bad battery that would start runs fine but had a bad cell and would caught cause issues with any sensor that requires a reference voltage. Also depending on how long your battery was bad before you replaced it Those sensors could have been going bad and due to a low voltage coming off your old battery never failed their own self test to actually throw a code.

 

Well, here we are two years later and I'm still dealing with the p2241 code, LOL. I replaced the sensor again and the CEL stayed off for a couple of weeks, and then gradually started coming on again. It's frustrating because I'm thinking of selling the truck, but it'll be hard to do with a CEL.