2000 mazda protege hesitation
 

Hello All,

I am new here and just purchased a used 2000 protege for my wife. I really like the car. It is fun to drive and was in very good condition. The car spent most of its life in Florida and has never been driven in the snow. It has only been here in Michigan for 2 years now. It was also owned by the same family during its lifetime and was obviously well cared for just by looking at it. When I bought it the owner disclosed that it had a CEL on, and that he checked it out at autozone who told him it was a problem with the catylic converter. He stated that it didn't effect the performance of the car. I test drove the car and it seemed to drive wonderfully, so I decided to give it a shot as the price was good, and figured I could fix any minor problems it may have. The owner had also put a good deal of $$ into fixing everything else with the car, i.e. suspension, timing belt, new tires, all new belts, hoses, etc.

Below is a detailed link to what I have done to the car so far, and have seemed to improve most of it, but it still has a very slight hesitation problem at highway speeds. Other than that it runs well now. Please if anyone has any ideas let me know.



https://docs.google.com/spreadsheet/...1E&output=html

I discovered one of the 'molex' connectors has a broken locking tab on the coil pack. does anyone have an idea where I can get another connector to solder in and repair this?

I checked both coils resistance. should be between 7 & 12 ohms. One of the coils seems quite dodgy getting a consistent reading, the other one seems to give me 11.87 all day long. Does this mean it is bad? or maybe I need some sort of contact grease in there?

I should also note that the hesitation problem started when I cleaned the egr and ports... seems that this may have fixed the cel, but caused the slight hesitation as shown on my chart from the first post. any thoughts anyone????

Actually the hesitation seems more like a "lurching" forward. Does this sound more like the coil(s)? The resistance checked good however. Maybe I'll just replace the wires,plugs,boots & coils and see what happens?

p0402 code on now
 

p0402 code on now cel

The lurching sounds like the coil. I’m on my second replacement. (189K) Misfires kill your catalytic converter.

P0402 sounds like something else.

Good Luck,
Walt

thanks for the reply Walt. The coil is what I thought too. Changed it and no difference. Also replaced all the vacuum lines.... still stumbles at +45 mph. I'm going to test for excessive back pressure in the exhaust as soon as my tool arrives. I should also mention that code P0420 is on now for the CC. I removed it and could still see light through it so I'm not sure, but I'm going to check the exhaust pressure anyways....

I should also note that the car seemed to run fine until I cleaned the EGR ports and cleared the P0402 code "excessive EGR" that problem seems resolved now but has been replaced by the stumbling??? weird...