Odd CEL problem

[danacosta24]

Hey guys,

I have an automatic 2009 GS sedan. I'm having a weird CEL problem. First off, this problem began about 2 months ago when I wired some Halo's. Everything was fine for a bit, then the CEL came on probably about 5 days. So I grabbed an ObdII to see what it was, it just came back as an error. Tried a few times, same problem. So I disconnected the halo's, did some research and found that it may have been triggered by not having a clean ground to ground connection (it was my first time wiring anything, I didn't know any better).

I drove without the halo's connected for a bit. CEL turned off. Reconnected the halo's with a better ground connection and everything was good. Stayed that way for a few weeks. Last week, the CEL came back on. Grabbed the ODBII again, error again. Haven't had time to do anything about it, so drove with it and noticed that 1 time, there was a bit of hesitation when my car was shifting itself from 3rd to 4th. It was nothing major, and probably lasted no more than a second. I was going to call the dealership, but since it was 11 at night, I was going to wait until tomorrow. The next day, went to start my car, CEL was off. A few more days pass, then the CEL came back on. So this time I've noticed the hesitation twice. I do a lot of highway/rural driving and it doesn't hesitate when shifting after a cold start. It only has done it when I have been driving at 100km/h for a bit then slow down to around 50ish when passing through a town or whatever. When accelerating to get back on the highway- from 50 to 60 ish when my car is trying to shift from 3rd to 4th- that's when the hesitation happens. Not for long, this is about 2 seconds, enough for me to notice and look down at my speedometer, but then it goes back to normal. And this didn't happen every time, only twice in that situation, but for my commute to work that happens 4 or 5 times a day.

I should also clarify what I mean by hesitation- I am pressing the gas, and have to press a little harder than usual before it engages.

So I read up on that, and read it might be my MAF sensor and or wires.

Was going to deal with it tomorrow. Drove home with the CEL on. Stopped to get a bite to eat quickly. Jump back in my car and the CEL is off now.

I have no idea what this is, and I don't want to go to the dealership for them to just not see it happen now.

Any ideas?

[S.F.W.]

Aside from the halo's, do you have an intake ? CAI or SRI ?

[danacosta24]

No performance mods.

Just halos, HIDs and a sound system

[jaimie08mazda3]

No performance mods.

Just halos, HIDs and a sound system

Where are your halo's run to? A fuse of some sort in the engine fuse holder? You could be putting the wire into a fuse that has something to do with the engine. Try another fuse and see if that works.

[danacosta24]

That's a good idea, I have them wired to be on whenever the car is on. I'll try somewhere else, but as of now, the CEL is still off

[jaimie08mazda3]

That's a good idea, I have them wired to be on whenever the car is on. I'll try somewhere else, but as of now, the CEL is still off

My thought is that your wire was screwing with the fuse causing you to have a code going haywire. And when the fuse is partially in it will work but it might send mixed signals to the car itself. Which fuse did you use exactly?

[danacosta24]

My thought is that your wire was screwing with the fuse causing you to have a code going haywire. And when the fuse is partially in it will work but it might send mixed signals to the car itself. Which fuse did you use exactly?

@jaimie08mazda3 I've got it wired to Eng Bar 3- number 33 on the fuse box diagram. I've just got the wire wrapped around the fuse and the fuse put back in place.

In hindsight, that seems like an awful idea for wiring. I think I got the idea from someone on youtube running the remote wire of an amp like that.

Any ideas for where/how would be a better place to wire them?

[jaimie08mazda3]

@jaimie08mazda3 I've got it wired to Eng Bar 3- number 33 on the fuse box diagram. I've just got the wire wrapped around the fuse and the fuse put back in place.

In hindsight, that seems like an awful idea for wiring. I think I got the idea from someone on youtube running the remote wire of an amp like that.

Any ideas for where/how would be a better place to wire them?

I don't find its an awful place to do it. Mines wired in the fuse box as well. My remote wire is ran off my cigarette lighter for the last 7 years haha and even when I put my deck in I never changed it. But always make sure the fuse is in fully. That could have been your issue all along. Between that and depending on the GA your wiring is could also have been the issue. But hey if no check engine lights then your good to go.

[TheMAN]

even if the wiring is good, electrical noise will do all sorts of craziness to the PJB, if you had it connected inline to the rest of the lighting system.... you can try to get around this by powering the halos directly and controlling them via a relay

[danacosta24]

so the CEL came back, I unwired the Halo's completely and reset the CEL and it was fine. Then it just came back on with no halo's. I don't know wtf to think. I'll try to see if I can get a code tomorrow.

[danacosta24]

Upon further research.. it could be a spark plug issue. My car is certified pre-owned under- thus under warranty so I've got all my maintenance done through the dealership. Does anyone know if they check your spark plugs on a regular oil change?

[danacosta24]

Good news- Took it to the dealership and they determined it was an O2 sensor in bank one that was causing a high air fuel ratio, running too lean. They replaced it and it fixed the problem

Bad news- It wasn't covered under warranty so they slapped down a nearly $400 bill. It wouldn't be bad if my car wasn't on the verge of an oil change, 96k maintenance check, and rust proof.. the fun never stops!

[Hyperion]

Good news- Took it to the dealership and they determined it was an O2 sensor in bank one that was causing a high air fuel ratio, running too lean. They replaced it and it fixed the problem

Bad news- It wasn't covered under warranty so they slapped down a nearly $400 bill. It wouldn't be bad if my car wasn't on the verge of an oil change, 96k maintenance check, and rust proof.. the fun never stops!

Uh, $150 from rockauto.com and install yourself in 30 minutes.

[midnightfxgt]

When you had the OBDII scanner, and scanned the error, you would have got more help and info, saving you hundreds.

[danacosta24]

Waited a few weeks before wiring my Halo's back directly into the fuse box with no CEL. So i wired them back in using an add-a-circut fuse. CEL came back on instantly.

Reset the ECU and wired the Halo's using a rocker switch instead, and has been fine ever since.


Weird.

[TheMAN]

and why you still haven't wired the halos to be relay powered? it's much safer