I am working on a 2006 Elantra and it will do nothing but idle. Soon as I give it gas it dies out and stalls. It had a bad cat blow the exhaust manifold and the manifold and cat have been replaced. It showed a misfire code on # 4 cylinder and O2 sensor bad. Cleared the codes but still only does nothing but idle. Any thoughts or ideas on what I could check ? New to working on Hyundai's

 

Who did the work?

 

Another garage replaced the exhaust manifold and cat about a year ago from what I was told by the owner

 

Would like to provide a worthwhile answer, but there is a lot of missing info here.

We don't know if this problem came with the vehicle or developed later or what ???

There could be several reasons for the condition and to just throw out a bunch of nothings is not smart.

Could you please provide the whole story, without which it is impossible to offer anything worthwhile. Thank you.

 

Ok the vehicle has been sitting for about a year of a little longer and just brought to me to look at. It has 250000 miles on it and it had a misfire on # 4 cylinder. and O2 sensor code on it. From what I was told the exhaust manifold and the cat right below it was replaced because it was bad and the exhaust gasket coming off the engine manifold was leaking because the cat was bad and restricted. When you start the engine it just idles and when you give it gas it stalls. I removed the plugs and its getting good fire and has new wires on it but the plugs are carboned up and pretty black. I was going to check the compression because of the mileage but have not yet. I see that this vehicle has a lot of sensors and I am very new at working on a Hyundai and I saw the forum and thought I would ask. And maybe someone would give me some advice or thoughts on what I could check to get started on what could be the problem.

 

The plugs being carboned up tells us it is running very rich.
What was the oxygen sensor code?
If a butcher job was done and the O2 sensor is getting extra air it could be telling the computer to increase injector pulse width meaning add more fuel which could be the reason for running rich.

We will try to stay with you to find what is going on and will offer some suggestions for you to consider so it gets straightened out, what do you think ?

Do you have any kind of test equipment to use ?

 

Not sure what the O2 sensor code was I erased the codes thinking that might be the right thing to do and never wrote down the code number. I also checked the fuel pump and I can hear it come on and its gettting voltage to 1 wire at the fuel pump. So
I removed the fuel line and put a hose into a gallon jug and turned the key on and its not pumping any fuel through the line. I dont know it a sensor could be causing that or if it should pump fuel through the line like I had it hooked up?