Ok I am know showing 12 codes they come back to low coolant temp thermostat cylinder 7 misfire and both banks of o2 sensors this literally went overnight lol
I will list the codes because people will ask for them but my main question is could the coolant and O2 codes cause the cylinder 7 issue? I really dont want to have to pull the intake to do the coils lol
any help is appreciated there is also an emission code in there but it seems to be related to the fuel tank return?

0491 0441
0159
0161
0126
0130
0171
1171
0174
1174
0307
1412

 

Someone correct me if I'm wrong, but doesn't burning coolant kill O2s?

OP, was your coolant low?

If my theory is correct, I'm betting you blew a head gasket which is leaking into #7, causing miss, and killed the O2 on that side.

Well, that wouldn't explain the other O2 sensor though. Is it possible that one was already throwing a code?

I'll look up each of these specific codes in a bit. For now this is my preliminary theory.

 

no it was never low on coolant or ran hot the thermostat was iffy as at times it ran cool until it opened and there is NO water in the oil or vice versa so NO blown head gasket
not even close the car runs smooth just every now and then you can feel the slight miss at idle no smoke out of the exhaust the main cause for the number 7 is the coil

 

PS the code was NOT low level it was Low coolant Temp

 

p0491 - SAI Bank 1
p0441 - Incorrect Purge Flow
p0159 - O2 slow response bank 2 sensor 2
p0161 - O2 heater circuit bank 2 sensor 2
p0126 - Insufficient coolant temp
p0130 - O2 sensor circuit bank 1 sensor 1
p0171 - Bank 1 too lean
p1171 - Manufacturer Controlled Fuel and Air Metering
p0174 - Bank 2 too lean
p1174 - Manufacturer Controlled Fuel and Air Metering
p0307 - Cyl 7 misfire
p1412 - Manufacturer controlled aux emissions controls

 

You've got some real problems, my friend.

Firstly, you need to replace that bank 1 upstream O2 sensor. It's bad one way or another. I'd recommend doing the upstream on bank 2 at the same time. They like to be replaced in pairs. The Walker sensors work well and they're more affordable. You can find them on RockAuto.

You also need to replace your purge valve. There is a Hyundai part number that is a direct replacement. I can't remember the part number. Get the genuine Hyundai part; NOT the Dorman branded part. The Dorman part is NFG; they die quick.

Have you looked at the Cyl 7 spark plug? Reading spark plugs is a huge help for diagnostics, even with all this fancy new OBD2 tech.

I am also betting that you have a bad MAF sensor, though replace the O2 and fix the purge valve before making that determination. You can try spraying some MAF cleaner on it to see if that helps as well. Only do that with the MAF unplugged and give it time to dry before plugging it back in.

Also, if it's running too cool because of a sticking thermostat then you need to replace that as well. That will certainly cause issues over time such as carbon buildup and premature failure (and clogging) of your catalytic converters.

 

thank you
On the Maf sensor does it need to be a Bosch unit or is there another unit that will work good? I have seen them for 35 to 50 compared to bosch at well over a 100
on the 02 sensor a lot of people say use only Bosch any feedback on that?

 

The public opinion has changed on the O2s. Definitely go with the walkers. Bosch o2s seem to have plummeted in quality. I personally got two that were DOA and so have a bunch of other people.

I've heard the you should get a Bosch MAf, but I never have had to replace mine. I'd say as long as you get a good name brand you're probably fine, but avoid Chinese generic ones as well as refurbished ones.