i have a 2005 hyundai elantra gls ... at about 61k my exhaust would make a choking noise when i would shut it off .. the air doesn't flow smoothly out of the exhaust when i start, drive or shut off my car ... its also hurting me on gas ... ive changed my spark plugs and i've also done a smog check and everything passed .. what could be the problem?

please help me , thank you

 

Sounds like your catalytic converter is plugged. The fact that the car passes it smog test is interesting. Have you had the exhaust system inspected for obstructions?

 

i just did my timing belt and i know the guy who owns the shop .. so he did a free smog check for me and everything passed .. it passed with very low emissions even lower than average emissions .. catalytic converter passed and is not clogged, exhaust passed and is not clogged .. i have the whole paper with me .. i next changed my spark plugs too which i dont think really relates to it .. but it was part of my 60k service

 

this is my smog check vehicle inspection report

PCV = pass
Catalytic converter = pass
fuel cap functional = pass
fuel cap visual = pass
spark controls = pass
vacuum lines to sensors/switches = pass
wiring to sensors = pass
fuel evaporative controls = pass
mil/check engine light = pass
carb./fuel injections = pass
other emission related components = pass
oxygen sensor = pass
liquid fuel leaks = pass

 

So did the problem occur just after you did the timing belt? Did he put a potato in your exhaust?

 

no, i just did the timing belt on 12/29/08 ... the exhaust noise started happening at around 61k (so about september/october of 2008) and i changed my timing belt at like 62789k miles ... he didn't put a potato in the exhaust but i did to see if there were any leaks from the pipes ... i did it one early morning and i didnt notice any leaks or anything