Check Engine Light

My check engine light came on a week and a half ago. It came on after I got bored at a stop light and turned off the overdrive and then back on (don't think this had anything to do with it). I stopped at an Autozone a few days later and had it checked out when I got my mom's car a new alternator, and a code didn't show up. The guy helping me and I were a little confused so we went back out to the truck and he asked me when it comes on and I told him after I crank it. He had me crank it and whaddya know, it doesn't light up. Fast forward about three days later and it comes on again. I currently have a hole in my muffler and a muffler is on the way to replace it. Do you think that could be a cause? I've already checked the gas cap to make sure it was tightened. I'm just confused because it didn't throw any codes, so any ideas?

Any thoughts or advice is much appreciated.

 

It's odd that after the CEL, you didn't have a code, as they usually stay in the memory until it's cleared. Did you disconnect the battery in between the time the CEL came on and you had the codes checked?

I would suggest getting a OBDII code reader.

I have this one.

for Android Phones ONLY - Wireless Bluetooth Diagnostic OBD2 Scanner Car Code Reader and Scan Tool for All 1996 & Newer Vehicles ELM327 Compatible OBDII

https://www.amazon.com/BAFX-Product...?ie=UTF8&qid=1495560072&sr=8-4&keywords=OBDII

Some apps are free, I have the Torque app which was like $5 I think.

Best $20 I've spent in a while. You can hook it up to your smartphone and leave it connected while you drive. Then just drive around normally and if the CEL comes on again, check for codes again.

 

Thanks for the info, I'll look into that product. To answer your question from before, I didn't disconnect my battery or have it cleared. It was just normal day-to-day driving for the few days before I stopped at Autozone.

 

So did the CEL come on and stay on until you had Autozone check it? or did it go on, then off again fairly quickly?

There is a possibility that it may not be throwing a code because of something like a emissions test not being complete, or perhaps Autozone used a crappy reader that couldn't read that code (I'd like to think autozone uses a commercial grade reader).

Would be odd for an emissions test to not be complete, but you never know. Some tests need pretty specific driving conditions to complete, and (again) I would like to assume that the Autozone folks would check that, too...

I did a little searching around, and another possibility is a bad computer is just throwing an erroneous CEL with no actual codes.

But hopefully driving around with the OBD hooked up will help narrow down the issue. Besides, the OBDII's are just handy to have anyway to help track gas mileage etc...

 

It came on and would remain on whenever the truck was running. They checked it at Autozone and it was still on. When we turned the truck back on the second time to recheck after the computer didn't show any codes, that's when the light didn't come back on. I may bring it later this week to other auto parts stores, O'Reilly's, Advanced, and NAPA, just to see if they can read a code. May buy a scanner while I'm at one of those.

 

2nd on getting an OBDUII reader.

Don't get this one. It'll make your ABS light blink.

$23 Foseal Wifi OBD2 Scanner, Car Code Reader Check Engine Light Diagnostic Scan Tool for iOS and Android

https://www.amazon.com/Foseal-Scann...?ie=UTF8&qid=1495571102&sr=8-3&keywords=OBDII

 

Update

Stopped by at an Advanced Auto Parts yesterday and the man that helped me did pull of two codes. Both of which were for parts in the emissions (i.e. an oxygen sensor or something like that). He said that their code reader couldn't give detailed enough information to be able to say exactly what was causing the check engine light to go off. He recommended taking it to a garage because they'll be able to tell exactly what it is and he also informed me that they should do this for free. I then told him that there was currently a hole in my muffler and he said that it could also be the cause. I am taking it to my local Toyota Dealership tomorrow to have it checked out to make my mom happy, because she isn't comfortable with me driving an hour and a half away with the check engine light on to scrap some metal in a buddy's great grandmother's yard. So hopefully I'll be able to get it to go away or find out what it is exactly this Friday so I can go Saturday!

 

02 sensor is an easy fix as long as the bolts aren't rusted to the studs.

 

That's good to know, but hoping it's just the muffler since I already have one on the way and it's one less thing to buy.

 

No doubt. I think the 02 sensor is 100something dollars too.

 

Yeah, would rather not spend that much on top of a muffler. Considering it's hard enough gathering money as a high school student.

 

I know how you feel. I just spent $1000, a full Saturday and half a Sunday replacing all my AC components...compressor, condensor, evaporator, high pressure switch, Evaporator, expansion valve, oil and all the other things. While we were in there we replaced the timing belt along with the tensioner, water pump, idler pullies, thermostat, lower radiator hose, all the belts and fan clutch. Youch.

 

I'd much rather be spending money on modifications than repairs and replacements. Oh well. My truck might not be finished like I want it in a year, but hopefully it'll get to where I want it soon enough.

 

I'll keep this updated tomorrow and then if we figure out what's making the check engine light go off.

 

No kidding! I was going to get rid of my bed and build a pop top aluminum camper, but I did this instead. The camper will have to wait till next year.

 

Your truck looks great! Can't wait to see what else you do.

 

They quoted you the Bosch one didn't they ? Autozone quoted me the Bosch one lol $100.00. No thanks, came home went straight to EBay And found this one

 

I got a toyota OEM one on Amazon for about $100...it was awhile ago, I don't quite remember. I try to stick to OEM being that I'm planning on keeping my truck until at least 2030. I'm sure the other brands are okay. But, the OEM one lasted 200,000 miles with no issues. I'm okay with spending a little more money on proven parts.

 

Do you happen to know the two actual codes from when they scanned your ECU? Also, when changing out O2 sensors or AFR sensor, Yotas can be pretty picky about which brands are used on their electronically controlled systems. You probably only want to source Denso brand(who makes the OEM sensor for Toyota) or if you enjoy paying the Yota mark up on parts, any dealer or online parts dealer.

 

Thanks for the advice! And no I do not. Maybe the info I get from my local dealership today will help. I'll keep whosever interested in this thread posted.