ok im new to this forum and ive been using the search tab and have not found a solid answer yet.. i own a 1999 4cylinder 5spd Mazda B2500 with 101,000 miles..

in the morning or after the trucks been sitting for a few hours, when i start it up it kind of sputters and bogs down for a little while (about a half mile or so) then drives perfectly fine.. im thinking its the Catalytic converter but i could be wrong..

also my ABS light is on sometimes.. when braking it brakes normal usually, but there are times when they seem real sensitive and would lock up and screech very easily(have the same issue with my F150 every now and then)..

check engine light is not on btw

i would appreciate any input on what could be wrong and also possible ways to solve these issues.. thank you

 

If it was the CAT it would always bog and sputter under load, unless its just the fact your not giving it enough warm up time, then I'm going to vote that maybe something in the "auto choke" system isn't working rite. Hows your air filter? Clean the MAF, clean the IAC. Anything in the path that the air takes into the truck.

 

it has a new IAC, MAF is clean and air filter is new... ill clean all that stuff again to be sure.. also it seems the cat is making noise sometimes.. i hear a rattling sort of noise which i believe is coming from there..

 

just to eliminate the possibility of the problem being the cat would adding something like a cherry bomb glass pack in place of the cat work fine or would performance/fuel economy suffer? its only a 4 cylinder so i dont want to just put a pipe in place of it because i dont want to sound like one of those annoying rice burners..

 

a rattle from the cat can be the heat shield

 

yeah thats true but it doesn't sound like an external metal vibration noise.. it sounds mor internal.

would replacing the cat with a cherry bomb glasspack harm my gas milage or performance at all? i know theres an o2 sensor after the cat but if its like my f150 then it does not affect the air fuel mixture.. it will just kick the CEL on.. i dont like catalytic converters and would like to remove it without causing a loss in gas milage..