Hello,
I've got an '02 Millenia-s that has been throwing error codes for months now. I took it to two nearby repair shops; neither one could figure it out (although not sure how much they actually tried).
I'm getting, mostly in this order:
P0105 - Manifold abs. pressure
P0170 - Fuel Trim Malfunction (Bank 1)
P1173 - Feedback A/F mixture Control (H02S21) HO2S Bank 2 Sensor 1

Sometimes also get these:
P01173 - Fuel Trip malfunction (Bank 2)
P0400 - Exhaust Gas Recirc. Flow Malfunction
P0455

OK, from reading around on this forum, I've noticed that the millenia is notorious for vacuum leaks, mostly in the T's. Is this the most likely culprit? If I go ahead and ask my repair guy to replace the t's and hoses, how likely is that to be the solution? I know that the labor can be a lot for this. I was thinking of having him do some other work while he's at it (sparks, timing chain, belts, etc.) to save on the labor.

Any advice would be appreciated, including other possibilities, or things that I should check for.

ALSO - if anyone knows of a great Mazda mechanic in the Southeastern MA area, please let me know.

Thanks!
Paul D.

Any advice would be appreciated

 

FWIW, if you can clean up the absolute code P0105, you'll prbably clean out most of the rest. I would suggest look at a manifold leak.

 

wrong. 0105 is map sensor CIRCUIT. i have NEVER heard of a map sensor going bad. i have had a vacuum leak throw a map sensor code a LOT. 0170/73 are CLASSIC vacuum leak codes. fix the vacuum leaks, and i bet all 3 go away. 1173 is heated o2 sensor, front left, pre cat. however, this can also be related to the vacuum leaks, because now it is running lean, and the sensor cant compensate. fix the vacuum leaks, this might go away. the other 2 are evap codes. most common is the gas cap, AND, vacuum leaks. fix the vacuum leaks, yada, yada. to get to all the tees and the vacuum lines, the intake has to come off. not a difficult job, but a lot of stuff has to come off, so it takes a long time. if your spark plugs have not been changed in the last 60k, this would also be a good time to change them. and get the correct ones, or you will have to go back in. this car does not have a timing chain, it has a belt. and 105k is the interval for the belt. i would never do a belt unless all the associated parts are also done, tensioner, tensioner/idler pulleys, and serpentine belts. you should also strongly consider the water pump. it sits behind all of this stuff, and if the water pump goes, all this stuff will have to come off to get to it. however, adding the water pump will easily double the labor on this job. i can also guarantee you the motor mounts are bad. mazda mounts are liquid filled, NO OTHER aftermarket place has liquid filled mounts. places like ebay will send you solid mounts, and the 2.5 mount is different from the 2.3, but few people know this, so you might get 2.5 mounts. one of which will hit the hood and leave a mark. i would also change out the coolant hoses, at least the upper and lower, and thermostat bypass. valve cover gaskets should also be considered. cost for all these parts and labor will be about what the car is worth. more if whomever does it has never done this on a 2.3 before, and most likely they will **** it up, and it will have to be redone. bottom line, if you cannot do the work yourself, you should get rid of the car. i know for sure i would not go back to those 2 places that cant figger out a simple vacuum leak. a shop that has never done these jobs on this car will just look up the flat rate, look up what parts they THINK they need, and give you an estimate. well, the flat rates on these jobs are very ambitious. i guarantee you the shop will NOT be able to complete but about half the job in the flat rate time. so, they will then start to cut corners, and not do a complete job. they will also discover that a lot more parts are needed. this translates to way more time, and cost to you. you are looking at the possibility of getting the car back in worse condition than what it was. and dont think the dealer can help, they are in the same boat. they will just charge you more. beware

 

Thanks both for getting back to me so fast, and with such great info. It seems I'm on the right track with the vacuum leaks anyway. I don't think I have the skill or time to do this myself. But the car is in great shape, only 80K miles so I would not consider getting rid of it. I will ask one of the shops if they'll do the vacuum hoses, sparks, coolant hoses, whatever they can reasonably do, and that's it. I primarily want the engine codes fixed so I can at least pass inspection.
Hopefully before then someone will also be able to recommend a great Mazda mechanic in my area too (S.E. MA).
Thanks again,
Paul

 

I'd like to take a shot at some of this myself. I have the shop manual, but I'm just looking for advice on how to go about replacing the vacuum hoses. I know I need to get about 25 feet of 4 mm inner dia. vacuum hose and 5 t's. But the vacuum hose routing diagram for the 2.3 is so complicated I don't know where to start. Can you tell me which hoses I should replace, and in what order? Also, what do I need to remove? Should I just start taking stuff apart until I can get to it? Any advice would be appreciated, thanks!

 

the intake has to come off. when you remove the plastic cover that says miller cycle on it, you will see the part of the intake that bolts to the compressor. it has the abv on it, and on the passenger side, it splits and one goes to the rear intercooler, the other goes the to front intercooler. once you remove that, all the vacuum hoses and tees are exposed. and there are only 2 real 'T' shaped tees, the rest are 'Y' shaped. actually, one end is straight, and the 3rd outlet branches off at about a 45 deg angle. the 'Y's hardly ever leak, but both 'T's break all the time. all you have to do is replace each length one by one; remove one hose, find the other end, then cut the exact same length, replace, move on to the next one. that is what a shop will do, and that is another reason the flat rates will be way less than actual time. you can probably get by with reusing the 'Y's, but if you have metal ones, now would be a good time to replace them. if one of them breaks, it will take the same labor to redo it. btw, i simplified this, because there is a lot of stuff besides the intake that has to come off. just be patient, and have a nice area like a table where you can put the parts you remove, to keep them in order. and i would plan on a couple of days the first time, leave yourself plenty of time. dont make it a deal where you HAVE to use the car say, to go to work, and think you will get this done in a weekend. because if you mess up the vacuum line connections, you will be doing it all over again. but each time you will get faster. however, the extra speed will be negated by the pissed off factor, because you will be mad

 

keninn,
Great advice, thanks. I'll plan for plenty of time to do this. And I'll be prepared to get mad too!
Paul

 

Hi, Keninn,
I hope you can answer a couple questions before I start on this project:
* Exactly what size of vacuum tubing do I need, and about how much should I buy? Is it 5/32" i.d.?
* I take it I should buy 2 ts and 3 y's?
* In the shop diagram it shows a lot of gaskets to be removed, with 'R' for 'Replace'. Do I really have to replace them, and if so, how do I know what gaskets to get before I get in there & start taking stuff apart?

Thanks,
Paul D.

 

remember that the intake has to come off. once it is off, you will have access to all of the hoses and connectors. i also replace some of the spring hose clamps with the screw on type, we call them 'norma' clamps. especially the connectors from the intakes to the intercoolers, those are a pain to remove, so i replace them with the screw on type. there are a lot of other breather hoses that i replace the clamps, the factory spring-type clamp actually works the best, because it will expand and contract with heat, but they are a pain to take off. i hope you have a good selection of hand tools.

 

I've got lots of hand tools. Excellent info, thanks, keninn. I'll post back w/ more questions, or better yet, a summary of my successful effort.
Paul