At first car sputtered a little between 1000 and 1500 rpm. Gas mileage was also bad so I replaced spark plugs. Still a problem so I thought maybe water was in gas. I used a bottle of Heet to try to get rid of water. Still problem existed. A month later stopped at red light began to go when light turned green and car did not want to go pass 35 mph but rpms went high. In the beginning it seemed as though car wanted to breath better. I thought maybe it could be o2 sensor or fuel pump/filter. Someone suggested cleaning fuel injectors or carborator. Any help will be appreciated. Thanks.
My car has 101582 miles.
My car has an automatic transmission.
Hi There, What you are describing sounds like a clogged catalytic converter. The catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When this is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly. When this happens, the engine is forced to work much harder to expel these gases. This often results in the engine bogging down, hesitating, shaking and causing very poor fuel economy. This should also cause a check engine light to come on as the O2 sensors should be reading the incorrect amounts of oxygen in the exhaust gases if this is your problem. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your catalytic converter.
Have a car question? Get free advice from our top-rated mechanics.