98zoomzoom

Catalyst bank 1 under threshold?????

This is what the diagnostics said after my CEL came on last week,
anyone have a clue? I know it has something to do with the cat but, -under threshold? I dont know my cars pretty loud know too myabe my downpipe is rusted out. Anyone else have this prob???

Bruce95fmla

I will take a look in my FSM at home, when I get home and see if their is any mention
Bruce

98zoomzoom

thanks

kansei

It means that your rear O2 sensor detects that the cat is not operating effiecently. This is usually due to air leaks in exhaust or misfiring in the engine. A misfire may damage the converter.

98zoomzoom

Well I got to looking around and listening, on a cold start I can hear that my exhaust manifold is leaking, took it to a garage and the guy that usually works on my car said that the manifold was indeed cracked. Its kinda ironic that i have seen a few manifolds on ebay for $70-$90. But the thing is he tells me not to worry about it and drive it as long as I can stand it before replacing it???
Is it that hard of a job, I actually think I caould do this myself...
Does anyone know of some headers that would fit on my 1.5l????

turbonium959

Replacing the exhaust manifold is not that hard. And from what I remember reading on Ebay, those 1.5 exhaust manifold are less prone to crack, unlike the OEM ones. As for driving with a cracked manifold I have no suggestion.

midnightblue97

Weld it??

Bruce95fmla

to replace it you would have to pull the upper bolts that connect the many to the head and pull the lower 3 bolts that connect the manifold to the lower joint pipe. You should be able to pull it up through the top, I don't see why not. and umm you should be set.

I actually forgot I have a spare manifold .. lol
on my car.. --- if you want it.

Bruce

Protege_kid

try taking it to the dealer, emission related problems should be covered under the five year warranty, the cat could be bad, I have replaced three at work, (@ the dealership) It wouldn't hurt to try.
I also wouldn't recomend welding the exhaust leak at the manifold. The cast iron manifold is not the best material to weld, it may crack in other places that is heated during welding.

98zoomzoom

Well I know nothing of a five year warranty but its almost over, I might ask the dealership.
Bruce if you have an extra ho much you want for it shipped to 42553?
thanks
-tony

Bruce95fmla

motor is in my backyard, I just have to pull the manifold and check it out first, make sure it is ok ... never know mine could be craked to lol ... but if everything is cool with it , it's your for 20+ whatever shipping is. I would just front the cost of shipping it and you can reimburse me..
let me know if you are interested.

-----------------------------
note to others: not parting out the rest of the motor just yet..
but I will
Later
Bruce

Samus

i had this error last summer, it went away after using about 5 full tanks of good gas and continuing to use good gas. the 1.5l's seem to ping if you use crap gas, even though mazda rates them for normal 87 octane. i dont get it, because it was obviously the problem as it was causing an occasional misfire which would immediately flip the engine light on. it would always happen at least 30 minutes after exiting closed-loop and driving consistently.

the obd2 stuff is really sensitive to engine performance, so its set off easily, even by a single misfire.

disconnecting the neg battery resets the softcode. you can try octane booster but in my opinion not many of them work anyway. its not the octane anyway, its just the fact that u might be getting gas with water in it.

after using good gas you will hear a difference in engine smoothness after awhile too. and before you call me one of those people who think 93 octane is for everything, please consider the 1.5l runs VERY high compression for a typical daily-commuter engine (190psi according to my compression test) but I also have 78,000 miles, carbon could be sealing off the rings a lil and causing abnormal compression, but it cannot be more than 5% out of spec. im sure everyone here has at least 180psi per piston chamber.