Hi guys, new to the site. I am having an issue with a 2000 Mazda Millenia with the 2.3L miller cycle engine in it. Last week the cel light started flashing and it was running bad, pulled codes out of the computer and I got 4 P0105 map sensor code, P0306 cylinder 6 missfire, P 0421 warm up cat efficiency bank 1, and P1524 charge air bypass. We cleared the codes and ran the car and the only code that has returned is the P1524 code. The car is not missing anymore, but it does not have any power at all. It runs but it is almost like the supercharger is not working. Did a bunch of tests on it based off the computer codes and came up with nothing. Not sure were to go from here, like i said it just seems like the car has no power at all, but does not seem to be missing anymore. One other thing i noticed is that when you start the car in the morning after sitting all night it blows a lot of white smoke out of the exhaust, after running it for a few minutes the smoke calms down, but is still there. The smoke that is coming from the exhaust smells like burnt oil. This car sucks to work on, not sure what to do. If anyone has any ideas please let me know.

 

well, dunno if i can help much. the 1524 charge air bypass is really not much, but if for some reason it is stopping the abv from operating, then you aint getting any boost. iirc, all the charge air bypass does is allow a more direct routing thru the intercoolers at higher rpms. but i DO know that if you take the compressor out of the loop, the car will run smooth, but have very little power. i know this because on the black car, the p/s pump pulley fubar'd, and i cut the belt, and drove the car home. on that belt is the compressor, water pump, and p/s pump. so i know what the car will do with no compressor. usually, when the abv circuit is bad, which is quite common on the 2.3, the ecu will put the car in limp home(tcs off/tcs lites up on dash, car will not rev above 2500). also, ce will throw 1525/26 and 1540. i think you should start by checking the vacuum system. this is a major problem with the 2.3. lots of vacuum lines, and several plastic tees. however, again, if there is vacuum leaks, you generally get 0170/73. also, i am not sure, but if you erase the codes, you also reset the system readiness monitors, and it runs on factory set default maps. after srm's come back on board, and it is in close loop, then perhaps the ce will store more codes? just a wag

 

I have not got any of the 0173/etc codes yet. I did check over alot of the vacuum lines I know there are a ton on this car and did not find any major leaks of broken lines. What do you think about the P0421 code could that be the root of my problems or is that just a code I should not bother with. I know the 0421 code has been in the car before, and it seems to come and go. It will be there for a while then clear itself and then come back later. I know this car has not had high test fuel ran through it 87 octane most of its life. Could that be causing some problems, and I am not sure if the plugs have been changed of fuel filter. The car has 113K on it and not very sure about the service records on the vehicle. What do you think about the smoke that comes from the exhaust apon start up, and the burnt oil smell coming from the exhaust. This car is driving me crazy and im not sure what to do with it. Let me know what you think. Thanks

 

0421 is right bank cat below efficiency. loosely translated, the post cat sensor is saying the cat is bad. if there was low miles on the car, i would say the sensor is too sensitive, but with the high mileage, your cat is dying. that has nothing to do with the low on power. both the plugs and the filter need to be changed at 60k intervals. your choice. however, if the plugs were bad, you should be throwing codes. the fuel filter could be clogged, and since i dont know how much down on power the car is, i can only guess. and i think running 87 octane is dumb.
no major vacuum leaks? a tiny crack can cause a big problem. if you found leaks, then there probably are more
the smoke from the exhaust should be blue or dark, if it is white, i would think that is coolant. if you are losing coolant, then you have a really big problem. was the car ever overheated? the smell of burnt oil could be oil dripping on the exhaust. is the car using oil?

 

Just to verify the right bank is the front bank or rear? As far as I know the car has never been overheated, but I do know the car is using oil. When I first pulled codes from the vehicle there was a cylinder 6 misfire. It is like the car is just running on the motor with no supercharger. I have worked on this car in the past and remember it having a lot of power. Like I said I did not find any kind of vacuum leaks, but I guess I could be missing one. Like I said I dont know if the plugs have ever been changed or the fuel filter either. Can you think of anything else.

 

the right bank is the rear. the japanese follow the germans. the right bank is always bank 1. but i dont know how the car would act if both pre cats were clogged, it would be down on power, but i dont know how much. can you verify your compressor is even turning? i cant think of any situation where the compressor would be not boosting, unless it was like when i cut the belt. but then it would overheat, and you would not have any power steering. all i can think of is the abv stuck open, so that the boost is being bled off. i think if you pull off the vacuum hose to the top of the abv, and plug it(otherwise the system will think the abv circuit is fubar, and it will go limp home), then you may get boost

 

The belt and compressor are still turning. Like I said the car has never overheated, but it does use oil. The abv is the cylinder looking component on the top front of the engine that has the rod coming out of it correct. If I plug off the vacuum hose it will generate boost correct.

 

i hope this works:
http://cgi.ebay.com/ebaymotors/95-97...Q5fAccessories

in the picture of the motor, the abv is in the 3 o'clock position. if the cover was on the motor, it would be about under where the green 'cycle' of miller cycle is. the brass 'hat' is the diaphragm that operates the valve. you should first check vacuum from various connections in the vacuum system to verify you are getting good vacuum. at idle, you should be getting about 18-20"

 

Hey kennin thanks for all the help. I looked at the abv yesterday and found one of the numerous vacuum lines going to it to have a leak. I repaired the vacuum line this morning. The car has been sitting idle for a few days now, and when i started it up this morning it began to miss. I took it for a ride and it smooths out above about 2500 rpm and it seems like it got its power back. When I got back from the ride the cel light began to flash and like i said the missfire is only there at idle, once you give throttle it seems to clear itself up and run a lot better. I noticed after coming back from the ride a bad smell coming from the exhaust, and the code I pulled this time is misfire on cylinder 6 P0306. Cylinder 6 is the last cylinder on the front bank towards the drive side correct. I still havent pulled the plugs yet, kinda dredding that job. Do you think it could be a plug or more likely the coil for that cylinder. Like I said the miss is only there at idle. Any suggestions would help. Thanks

 

generally, the front bank is ok. however, i notice that both #5(rear) and #6 seem to get the most oil in the wells. i would first start with a full plug change. while you are doing that, mark #6 coil, and move it to another cylinder. since it is the front, they are easy to get at. but dont skimp on the plugs, afaik, only the ngk 3741 is the proper gap. the rear bank is a ****, if you go to the other millenia site, there should be a tutorial. even then, expect to spend 4-5 hours, and i always pull the battery and the rear intercooler, because getting at #5 coil is a real pain. with the intercooler off, it is way easier. but to get the intercooler off, you gotta pull the battery. the egr nut is 23mm. i clean the heck out of the plug wells, brake cleaner works good. then, i put a really good silicon seal on the inside, esp around the valve cover gasket. this will stop oil seepage into the wells. but it's gotta be uber clean. if the miss follows the coil, then you have your answer. check the plugs, they will tell you a lot. expect them to be a bit oily or sooty, this car runs rich. since it cleared up and ran good, i would suspect a bad plug. if so, you are lucky. even if it is a coil, at least it is on the easy side to get at.