Hey guys I have owned several Mazda's over my life from a protege that my brother totaled to the 02 Millenia I just bought yesterday. I took the car for a good 30 minutes drive and did a good inspection on the car. However this afternoon the CEL popped on I took it to the autozone to see what codes popped out. Got P1250 and P0431. I bought the car from a private seller for 2950 and he told me that he was not aware of any mechanical issues. (Seems like that may have been a load of crap) I know from reading a bit that the codes deal with the Cat converter and PCR valve. What I am wondering is how likely is it that I will need to replace the cat and valve. I know that these can get costly if you have a mechanic do them. I am a teacher and being that I have 3 months left before summer break I really don't have the time to work on the car. The mechanic I would take it into give me a discount on labor and parts since my father in law works for him. Even so it seems like I would be looking at well over 1000 to replace both parts at once. The car starts with no hesitation, but once started it idles a bit rough nearly stalling out several times before it seems to normalize. I had to drive it from the school to home today and it had no problems at freeway speed and once home I let it idle for 20 minutes with no problems. I am starting to wonder if I should have just not bought the car. But it is beautiful inside and out and reminded me of my protege so I just couldn't pass it up. Did I make a horrible mistake???? Is this car destined to be a money pit? Should I just sell the thing and cut my losses?? I may take it back to the mechanic on Monday and see what my cost would be. I haven't don't the title transfer just yet so at least I wouldn't lose that money.

 

YES, YES, and YES

Mazda Millenia, especially since it is the 5th worst car ever according to: Yahoo!

5. Mazda Millenia (Engine issues, transmission issues and cheap interiors that just don't wear well.)

between the turbo/supercharger and the solenoids on that car it is hard to figure out.

Sell'er and buy wine!

 

I took the car for a good 30 minutes drive and did a good inspection on the car. However this afternoon the CEL popped on I took it to the autozone to see what codes popped out. Got P1250 and P0431. I bought the car from a private seller for 2950 and he told me that he was not aware of any mechanical issues.

Protege2Milly........and back to Protege, I guess.
Milly: this guy unloaded his problems on you. He took the battery negative off and stepped on the brake before you arrived for the test ride. That erased the CEL and turned the monitors off until you have driven it long enough.

When test driving a car you should ask about the CEL (did you ever have the CEL on?). After you get the answer ask the seller if he agrees with a scan. If he does not agree you may thank him for the time and walk away.
If he does agree hook up your reader and check if all monitors are on. If they are on and you have no trouble codes you can carry on with your test drive and inspection.
I am sure the Milly can be improved upon but I don't have experience with it. Hopefully another contributor can help you.
Good luck!

 

Well as much as I am thinking about getting rid of the car, I need a second car and doubt I can get what I paid for it back. I don't think I could get a protege for 2800 or less that didn't have problems do you? I don't want to buy new either so i 'm stuck with the thing i guess. It looks like I can get the cat for 230 or so from A company up in canda. The mechanic said maybe 250 to 300 labor which is reasonable the PRC I think will cost about 400 so I'm looking at 900 or so worst case. My thinking is drive it for a year sell it and get something else. Maybe a used 6 or if I can get really lucky a rx7. Live and learn I guess.

 

from the codes you posted, i can tell you have a 2.3(2.5 does not have these codes). while these codes are common, the dtc does NOT mean the part is bad. all they mean is that pcm has detected a problem in that particular circuit. most common on the 1250 would be a vacuum leak. parts for this is cheap, maybe a length of vacuum line, at what, couple bucks a foot? or a broke plastic tee-i use brass, get them from any pet store that sells fish tank stuff. however, the labor to fix this can be really pricey, even a disaster, especially if the person attempting the repair has never done this before. 0431 dont mean the cat is bad. again, THE MOST COMMON cause is an overeager oxygen sensor. and i mean REALLY common. so, say you install a new solenoid in an attempt to fix 1250. if there is a vacuum leak, guess what? you STILL GET THE CODE. and if the oxygen sensor is overly sensitive, and you install a new precat, guess what? YOU STILL GET THE CODE. so lets go to part 2. fixing the problem. first off, i would do a vacuum test. and now i question your choice of your "mechanic". because a vacuum test is so basic, i am shocked your "mechanic" did not do this extremelysimplea5yearoldkidcandoit. i suspect your "mechanic" needs to go back to school, and pay attention this time. the second problem, again, is simple. a REAL mechanic would probably try to DIAGNOSE why the code is thrown, instead of throwing parts at it until it goes away. a simple sniffer test would tell if the precats are below threshold. if your shop dont have a simple gas analyzer, you need to find a REAL shop. we have 2 99's, one we bought new, and another with 60k, used. both cars have had these and numerous other codes. both have had a precat, but only after flow was checked. both now have about 150k, and run fine. the engine is a miller cycle, which won several engineering awards for several years. no other car has this, and dont confuse atkinson cycle with miller cycle. and herein lies the problem. because this engine is so unique, it takes someone with true DIAGNOSTIC abilities to resolve a check engine lite. because, after all, a check engine lite means pcm has found a problem, and stored a dtc. what is a dtc? DIAGNOSTIC TROUBLE CODE. if i took one of our cars to a shop with a ce lite, and dtc P0431 stored to be fixed, and the shop told me it needs a new precat, i would ask for proof. if they had no sniffer test, or had not scoped the sensors, i would tell them where to stick it, and take my car back. and if you are just going to throw parts at it, why not start with the sensor first? it is a helluva lot cheaper, and a helluva lot easier to change than the cat, and most likely, if it IS the cat, which it aint, you are going to need a new sensor anyway.

now comes reality. my advice to you on this car is, if you cannot do the work yourself, and have to pay someone to, get rid of the car. it will eat your wallet. people tend to think all shops/mechanics are the same, therefore, go for cheapest. they all think the dealer is the most expensive, but they can fix any problem. you will end up paying someone to learn how to fix your car. and it wont be cheap. this is a unique car, it can have unique problems, and it takes talent to fix it.

 

Protege2Milly:
Keninn's response is hitting the nail on the head. How confident are you with the wrenches? Are you willing to learn a few new things even though it may be frustrating at times?
If your answer is 'not so much' then you may look again at a simple 4 banger without anything fancy attached to it. I would also advise you to look the other way when you see a rotary. Because what keninn said about the Miller cycle is also true for the Wankel engine.
The sticky "the unofficial user's guide to the protege" will give you a good summary of things you might incur with a normally aspirated 4 banger (protege, 626, 6, miata) that has 100K or more on it.

 

Very interesting, and wonder if this is the reason it was on the list of top 10 worst cars, due to it's complexity
Thanx for your insight.

 

keninn,
Thank you for responding to my post as it seems you are very knowledgeable on the Milly. The mechanic shop I go to has been around for a long time the guy is very knowledgeable about cars. He actually had another Milly two days before mine. It had an exhaust leak and something else wrong with it. The mechanic has not had a chance to preform the test you mentioned yet as I got to his shop 20 mins before closing and he was swamped.
What he was able to do was confirm the codes. He then get me a best and worst case scenario reminding me that it could be several places in between. He is going to give me a bumper to bumper run down of the car on monday. I'll update about what he says Monday. While I am pretty decent with fixing cars time is something hard to come by for me. I teach and have to kids so my free time during the school year is minimal. I do think the car is beautiful and the ride is amazing. I tend to agree keninn this car seems to be misunderstood and just needs TLC to be something wonderful. I admit that time to fix the car maybe be problematic. My concern is I need a second car and what it the likelyhood of either A) finding someone to either buy the Milly for enough to get a 4 banger without issues of its own or trade for one. B) If this mechanic is not up to the task can I find one who is or like you'd said will this just eat my wallet. The car is a beauty maybe I should post it on the sale forums and see if I get butes . I love Mazda cars but this Milly is making my head hurt lol. What's a guy to do. Tan and noggin thanks for your replies. I think a lot of this was just panic on my part no one likes to buy a car and have the cel come on the next day. I will see what the mechanic say on Monday and post an update here. If he toss the cat at me I'll ask him to fun the other test with me present so I know 100 percent that's what it is. Keninn again thanks for you post it was highly informative and gives me a little piece of mind.

 

Decided to do some minor research on the MILLER CYCLE:
In the Miller cycle, the intake valve is left open longer than it would be in an Otto cycle engine. In effect, the compression stroke is two discrete cycles: the initial portion when the intake valve is open and final portion when the intake valve is closed. This two-stage intake stroke creates the so-called "fifth" stroke that the Miller cycle introduces. As the piston initially moves upwards in what is traditionally the compression stroke, the charge is partially expelled back out through the still-open intake valve. Typically this loss of charge air would result in a loss of power. However, in the Miller cycle, this is compensated for by the use of a supercharger. The supercharger typically will need to be of the positive displacement (Roots or Screw) type due to its ability to produce boost at relatively low engine speeds. Otherwise, low-rpm power will suffer.
A key aspect of the Miller cycle is that the compression stroke actually starts only after the piston has pushed out this "extra" charge and the intake valve closes. This happens at around 20% to 30% into the compression stroke. In other words, the actual compression occurs in the latter 70% to 80% of the compression stroke.

ATKINSON CYCLE:
Atkinson cycle has been used to describe a modified Otto cycle engine in which the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold. The effective compression ratio is reduced (for a time the air is escaping the cylinder freely rather than being compressed) but the expansion ratio is unchanged. This means the compression ratio is smaller than the expansion ratio. Heat gained from burning fuel increases the pressure, thereby forcing the piston to move, expanding the air volume beyond the volume when compression began. The goal of the modern Atkinson cycle is to allow the pressure in the combustion chamber at the end of the power stroke to be equal to atmospheric pressure; when this occurs, all the available energy has been obtained from the combustion process. For any given portion of air, the greater expansion ratio allows more energy to be converted from heat to useful mechanical energy meaning the engine is more efficient.

The disadvantage of the four-stroke Atkinson cycle engine versus the more common Otto cycle engine is reduced power density. Due to a smaller portion of the compression stroke being devoted to compressing the intake air, an Atkinson cycle engine does not take in as much air as would a similarly designed and sized Otto cycle engine.
Atkinson cycle provides good fuel economy, it is at the expense of a lower power-per-displacement as compared to a traditional four-stroke engine.[3] If demand for more power is intermittent, the power of the engine can be supplemented by an electric motor during times when more power is needed. This forms the basis of an Atkinson cycle-based hybrid electric drivetrain. These electric motors can be used independently of, or in combination with, the Atkinson cycle engine, to provide the most efficient means of producing the desired power. This drive train first entered production in late 1997 in the Japanese-market Toyota Prius.

At this writing, most production full hybrid-electric vehicles use Atkinson cycle engines:

Ford C-Max (front wheel drive / US market) hybrid & plug-in hybrid models
Ford Escape/Mercury Mariner/Mazda Tribute electric (front- and four-wheel drive) with a compression ratio of 12.4:1
Ford Fusion Hybrid/Mercury Milan Hybrid/Lincoln MKZ Hybrid electric (front-wheel drive) with a compression ratio of 12.3:1
Honda Accord Plug-in Hybrid[4]
Honda Accord Hybrid (front-wheel drive)
Hyundai Sonata Hybrid (front-wheel drive)
Infiniti M35h Hybrid (rear-wheel drive)
Kia Optima Hybrid (front-wheel drive)
Lexus CT 200h (front-wheel drive)
Lexus ES 300h (front-wheel drive)
Lexus IS 300h (rear-wheel drive)
Lexus GS 450h hybrid electric (rear-wheel drive) with a compression ratio of 13:1
Lexus HS 250h (front-wheel drive)
Lexus RX 450h hybrid electric (four-wheel drive)
Mazda 3 SkyActiv (front-wheel drive) with a 13:1 compression ratio (12:1 for North America)
Mazda 6 SkyActiv-G 2.5L (front-wheel drive) with a 14:1 compression ratio (13:1 for North America)
Mazda CX-5 (front- and all-wheel drive) with a 14:1 compression ratio (13:1 for North America)
Mercedes ML450 Hybrid (four-wheel drive) electric
Mercedes S400 Blue Hybrid (rear-wheel drive) electric
Toyota Camry Hybrid electric (front-wheel drive) with a compression ratio of 12.5:1
Toyota Highlander Hybrid (2011 and newer)[5]
Toyota Prius hybrid electric (front-wheel drive) with a (purely geometric) compression ratio of 13.0:1
Toyota Yaris Hybrid (front-wheel drive) with a compression ratio of 13.4:1

Four-stroke engines of this type with this same type of intake valve motion but with a supercharger to make up for the loss of power density are known as Miller cycle engines.
A similar delayed-valve closing method is used in some modern versions of Atkinson cycle engines, but without the supercharging. These engines are generally found on hybrid electric vehicles, where efficiency is the goal, and the power lost compared to the Miller cycle is made up through the use of electric motors.

MILLER CYCLE:


ATKINSON CYCLE:

 

Here are some pointers:
http://repairpal.com/mazda/millenia

Specifically about the supercharger:
Supercharger Rebuild - Technical guides - Mazdaworld

And this here: