Why does your 1987 non-turbo rx7 jerk or studder sometimes as if the car while running feels like the car is choking?

Answer 1

pre catsFirst thing I would do is check the catalytic converters! Mazda put 2 pre cats on the second gen non-turbo. They are only needed because of cold starts. When the vehicle is started it will pass smog when cold. NOW we all know that when you drive your car to the smog shop it is not cold. I have gutted my 2 precats on my 88 gxl and left the main catalytic converter on and it passed California smog with flying colors. The tech told me it had the lowest smog numbers of any older Mazda he had ever seen. DON'T be fooled by a shop that says you need to replace your catalytic converter. My first rx7 (86 model) the shop told me I had a bad cat so I let them to replace it. Only to find out later that my first cat had plugged the second cat. The main cat was in great shape. But the shop hollowed out the first two and put an aftermarket one in place of the orignal main cat. That was not needed and they only wanted to make a sale. If your main factory cat is in good shape keep it cause most aftermarket ones can't handle the heat. Also you must have some kind of back pressure in the exhaust system to open the ports. DO NOT HOLLOW OUT ALL THE CATS!!!!!