What can make a 04 honda pilot have a hissing sound when you step on the gas pedal?

Question

I had my exhaust looked at 1 year ago a, was told I had only one side of the catalytic converter welded and some tiny holes near by. Well now it makes a hissing noise when I go to accelerate and the check engine light and vtm light have come on. It passed smog in February.

Answer 1

The only way to know what's wrong is to connect OBDII scanner and read the error codes. You can go to nearest AutoZone and get error code report for free.

Engine check light just means there is something wrong. Guessing what's wrong is pointless, the next step is always reading the codes with a diagnostic device.