[geddinwk]

I wouldn't confuse this steady voltage with your fix. After having the battery disconnect the car assumes it is only 20% charged, and bumps up the voltage according. Very few people know the alternator is controlled by a very complex algorithm and sensors. A varying voltage is mostly a sign of a healthy charging system.

Thx for posting this, I literally tell people here constantly how important a good electrical system is to our cars. And I'm usually meet with argument and disbelief.

I had gone to advance auto and was told the battery was at 75% so it makes sense that the 14.7v was to charged it up. After 1 day of driving the voltage is fluctuating between 14.2-14.6 but the interval is significantly decreased.

 

[geddinwk]

I know the car is a 2012, but the fuse bus breaking was pretty wild for me. I guess the resistance from the battery cable never being replaced weakened it? I have no idea. I love GM for the most part but their maintenance schedules and TSBs are minimal at times and don’t address the consequences of some issues

 

[geddinwk]

Code is back, I’ve read other threads and found that the alternator can over charge causing the ecm to short. So if I just completed tsb 14311 after having the car almost 10 years then the damage is probably done if its that. I’m going to check the connections to the intercooler at daylight tomorrow as well. Here’s to hoping its that instead

 

[geddinwk]

The main fuse breaking is probably coincidence. If you unplug your battery to change the the main fuse or the negative battery cable of course the codes will disappear.

your alternator seems to be working fine. The voltages are in range. It operates higher than a traditional system and will fluctuate depending on how discharged your battery is.

the code came back because the issue was not fixed. After disconnecting the battery your emissions monitors are reset, which includes catalytic convertor.

you are right about the Cruze being a smart system but it is not considered a high voltage vehicle. If you are getting a code for p0420. Chances are very high that you have a bad convertor.

don’t cheap out and buy an off brand converter unless you want to pay twice. the Cruze doesn’t like anything but OEM converters.

Yea I already regret making this thread. I used to have an estimated range of like 565 miles on a full tank and 625 if I was doing a lot of highway driving. Now it’s a flat 400. Even if the converter is bad I don’t see losing gas mileage because of it. I don’t have the bad sulfur smell and my freeze frame always happens at idle, which could be the substrate being worn in the cat. But doesn’t explain the loss of gas mileage to me

 

[geddinwk]

I can’t find any intake leaks. But I did notice the exhaust sounds like this, not sure if it’s normal. This is stock, no mods

- YouTube

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

youtube.com

 

[geddinwk]

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[geddinwk]

I drove it down the street and back and it blew 2 qts of oil all over the passenger side engine compartment. Only code is still p0420. My eggs are cooked lol. Any idea on what the issue is I’ll appreciate it. I guess a front main seal. I don’t know.

 

[geddinwk]

I drove it down the street and back and it blew all 4.5 qts of oil all over the passenger side engine compartment. Only code is still p0420. My eggs are cooked lol. Any idea on what the issue is I’ll appreciate it. I guess a front main seal. I don’t know.

Like there was no warning whatsoever that this was going to happen

 

[geddinwk]

Just an update. Had a short in the coil pack connector so instead of splicing a new connector in, I replaced the entire wiring harness. You can get it cheaper from some dealerships than others. Driven 500 miles and no check engine light. I didn’t even clear it. Just hasn’t come back

 

[geddinwk]

update, p0420 code came back but after running two cans of seafoam in the car the light went off by itself again

 

[geddinwk]

I've been keeping up with this thread in secret for 2 months. Same code for the cat. Ran catacleaner and it did nothing but I did also replace my coil packs about 4 months or so ago. Going to give seafoam a try and then replace my coil packs again as while i went for a 200mile drive (not the smartest but hey) i lost control to the ecm, got the stabilitrak crap etc so im assuming it started to dump fuel into my exhaust. Will try to remember and update this after i've driven with the seafoam and again if I end up changing my coil pack.

Some symptoms for me include slightly rattly(not so much that I think components inside the cat are broke) sound at higher rpm(right around 4k ), greatly reduced fuel economy and the car struggles to accelerate. I'm also going to trace my exhaust from underneath and see if theres a crack or hole anywhere.

I made a whole new post about p0420

 

[geddinwk]

I've been keeping up with this thread in secret for 2 months. Same code for the cat. Ran catacleaner and it did nothing but I did also replace my coil packs about 4 months or so ago. Going to give seafoam a try and then replace my coil packs again as while i went for a 200mile drive (not the smartest but hey) i lost control to the ecm, got the stabilitrak crap etc so im assuming it started to dump fuel into my exhaust. Will try to remember and update this after i've driven with the seafoam and again if I end up changing my coil pack.

Some symptoms for me include slightly rattly(not so much that I think components inside the cat are broke) sound at higher rpm(right around 4k ), greatly reduced fuel economy and the car struggles to accelerate. I'm also going to trace my exhaust from underneath and see if theres a crack or hole anywhere.

um… where is the rattle at? If you have a scan tool I would use it and see what your CAT temps are. This has definitely been a learning curve for me

 

[geddinwk]

I've been keeping up with this thread in secret for 2 months. Same code for the cat. Ran catacleaner and it did nothing but I did also replace my coil packs about 4 months or so ago. Going to give seafoam a try and then replace my coil packs again as while i went for a 200mile drive (not the smartest but hey) i lost control to the ecm, got the stabilitrak crap etc so im assuming it started to dump fuel into my exhaust. Will try to remember and update this after i've driven with the seafoam and again if I end up changing my coil pack.

Some symptoms for me include slightly rattly(not so much that I think components inside the cat are broke) sound at higher rpm(right around 4k ), greatly reduced fuel economy and the car struggles to accelerate. I'm also going to trace my exhaust from underneath and see if theres a crack or hole anywhere.

Is there any other codes or info you can give? It doesn’t sound like the CAT would be causing all those issues. Struggling to accelerate is a red flag for a cracked turbo housing or shaft since you are saying something is rattling. Other things it sounds like are head gasket, oil starvation notching lifters/etc. can you do like a thorough inspection of all engine components?

check oil, oil filter, coolant levels, oil leaks, coolant leaks, cat converter visual inspection, o2 sensor visual inspection, spark plug visual inspection, measure the oil that comes out the pan, etc. if you have a scan tool look at the fuel trims at idle, cat temp after a drive, o2 sensor graphs.

This will give you a better picture of what’s going on.

I never had a rattle, and if you just changed the coil pack you shouldn’t have to change it again for at least 5 years