CEL light came on. What could cause these codes?

[youlovemyep3]

Alright so my car threw two codes today.

P0420 - catalyst system efficiency below threshold bank 1.

I'm assuming this is either my stock wideband O2 going out, or the Cat is going bad? Thoughts?

The second one I'm kinda puzzled and have no clue.

P1298 - (ELD) Electric Load Detector Circuit high input.

What would cause this? I dont even know where to look. Thanks for any help.

[youlovemyep3]

Also, I don't notice any differences of the car when it comes to driving. I did notice a slight smell inside the car when I did a little fun driving the other night. Other than that, nothing.

[AKEP]

what mods do you have?

[ep3hatch03]

could be something as simple as an an o2 sensor i would start with that

[usedep3]

your cat is bad

[youlovemyep3]

Just intake, dc sports header and borla catback. I had a cel for the p0420 awhile ago but erased it. Then it came back with another code so I thought I might have done some damage. Lol. I'll start with o2. $156 at autozone. :(

[youlovemyep3]

Ok well I'm finally getting around to replacing this thing. Before I buy it though, I want to know which one you guys think it is. Cat or o2.

I'd hate to spend $150 on an o2 only to find out it's the cat..

[talonXracer]

If you have a DC race header the cat was removed and is no longer installed. The secondary o2 sensor probably needs a defouler setup added. The ELD code is usually caused by a sensors heater section shorting out and causing a load surge that fried the ELD.

[youlovemyep3]

Nope it's a DC shorty to a stock cat I think..

I just bought a Megan high flow cat off some site, so hopefully that fixes the issue. We don't have emissions here so I'm not worried about it not passing. I will most likely need a defouler too right?

[KevinEP3]

I had the same code and replaced the secondary o2 and the CEL went off for a week (long enough for inspection) and came back. Now I got another year to replace the cat. Try the o2 first since its $60 vs $400+ for the cat.