orion981

iTrader: (2)

Hi guys, I am having issues with the Evo and wanted to know if you might be able to shed some light on the subject.

Currently, my car is throwing a CEL (no number yet, working on getting one.) The car is getting horribly poor gas mileage (about 12 mpg), and the exhaust reeks of gas. My impression is that the car is running far too rich. The problem started about a week after I had the car dynoflashed. I brought it back and Al was kind enough to pay for some dyno time to check it out. He checked the air/fuel ratios and said they were fine, and the car put down about 280whp (I have an intake and turbo back exhaust.)

The car doesn't bog, either, so it doesn't seem like I'm loosing any noticeable amount of power. The people at Pruven said they think it might be a blown O2 sensor, but they have to check for sure. If this is the case, it might explain why the ecu is dumping so much fuel into the car (if it can't accurately read the amount of air, it probably wants to dump as much fuel in the cylinders as is possible, so as to prevent detonation.)

Anyone out there with an idea on what might be happening? Anyone have a similar experience?

orion981

iTrader: (2)

Nobody has any ideas?

P0300

iTrader: (3)

I had an old DC2 GSR that had a bad O2 sensor that was causing fuel smells inside the car and bad gas mileage as well. The car was also running rich as hell. This was on an Integra though, but the symptoms sound very similar.

ModenaTwinTurbo

iTrader: (1)

have the dealer check the code.........

Ed-

GREDDY

iTrader: (8)

Go to autozone, they will pull the code for free. Then come back with the code and we'll understand what's going on in the engine. Also autozone uses a pretty good obdII scanner so they more then likely can tell you exactly what the codes mean. Do this first, don't waste money going to the dealership yet.

Deca Auto

iTrader: (11)

I'd say it would be obvious you have a boost leak somewhere. But if the AF ratio says your running fine then im sure the front O2 sensor is bad. The cel is prolly the back O2 sensor reading your cat isn't burning all the excess gas.

mrbkkt1

iTrader: (6)

running rich, or maybe a fuel leak, or faulty sender unit on fuel pump. did you get in an accident recently or anything? hey don't feel bad, last milage check for me yealded 13.9 mpg. i drive really aggressive though.

orion981

iTrader: (2)

Thanks for the feedback guys. I'll drop by autozone now. As for going to the dealership, I don't think I'll go that route. The dealership near me seems pretty mod friendly (they have a aftermarket parts shop right in the shop, and were selling an evo with a mbc, and intake on it) but I'm not sure if it's worth the risk. If it's a blown o2 sensor, they'll definitely tell me it's not covered under my warranty due to my turboback exhaust. Instead, I will drop by Pruven and see what they can do. They're cheaper, just as experienced, and won't void my warranty.

No accidents at all, though the car was stolen a few months back (don't think it was driven though -- a long story I've already posted here once.) In addition to this, my Exedy hyper single plate clutch is starting to slip. My poor evo is all jacked up...

mrbkkt1

iTrader: (6)

Hey, i have a brand new evo and i'm getting less than 14 mpg. do you think it's cause i drive to fast?

Raman

iTrader: (1)

I'm going thru the same thing except that mine is running lean. The car runs like ****, pulls timing, poor fuel mileage, throws CELs, etc...

So I went to Autozone today, and they pulled a P0171 (System too Lean) and a P0134 (Heated Oxygen Sensor No Activity Detected). I'm gonna see what we can find out whether it's the 02 sensor, injectors (stock), or the coils/plugs. Then richen out the S-AFR...reflash......

asasin79

iTrader: (10)

i had similar symptoms...i was getting about 100-120 miles per tank. pulled the code and it was p0141 Heated rear o2 sensor malfunction i had to replace the rear o2 because of the problem. i also had to replace the cat after replacing both and getting my cams timed right i was good...btw rear o2 from dealership is like $350 hope it isn't busted. good luck bro.

vincent

ModenaTwinTurbo

iTrader: (1)

about the warranty, well just think about it, a flat rate guy gets paid close to if not exactly half the time he would doing a customer pay job than he does when doing warranty work. and then if the warranty *TRULLY* is voided (not talking about a filter and an exhaust) but something that the owner of the car *HONNESTLY* did (i.e. turn the boost all the way up to as high as it can go, or raise the fuel pressure as high as it can go) then if the tech working on the car doesnt say that the warranty has to be voided this flat rate technician now makes little to almost *NO* money at all, remember theese guys have bills and family too.

Now what about the sensitivity of the shop manager or the tech's working on the car as for warranty void is concerned? well that all depends on the type of shop the dealer might have, if its a small 3 bay shop located in a verry rural area usually they dont get to work on many evos and any little difference that they might see could frighten them and alert their senses in regards to the warranty. now a shop of a bigger dealer located in a bit more urban place where theres a bit of a higher abundance of evos those dealers are use to seeing things like 3" exhaust sys', intakes, aftermarket gauges, and even some ammount of electronics i.e. turbo timers and such. they know theese things wont hurt the cars. because some of theese dealerships sell the items.

now in regards to a mitsubishi dealership beeing a waste of time or money. i'll just explain the capabilities of a dealership to diagnose a problem as supposed to just going to a place with a free obd-II scan. the place with the free scan will probably have a scan tool and a haynes manual that they can sell you. Now a mitsubisi dealership has technical service buletins beeing updated daily sometimes 2wice a day or as need be in a computer that sits in the shop area with all the information a technician would need and more to be able to diagnose a problem. in adition to the tsb's the same computer has a feature called medic, with three options as to how to go about figuring out the problem. and for the 3 major types of scan tools that a dealer has, one is called midtronic its used to detect problems in the batery/charging/starting system mainly, the mut-II used for obtaining DTC's, osciloscope, ohm meter, volt meter, belt tension sensor, many many more options like auto run tests, the mut-III is a bit more complex yet easier to use than the mut-II this one is for the reflashes just hook it up to the car and it will tell you plain and simple it needs a reflash or it doesnt, along with many other features this one works with a laptop hooked up to it.

and also the information beeing written in the tsb's and other helpful service and update articles and features is all by mitsubishi engineers. a dealer also if they are trully having a serious hard time with the car they even get dirrect advising from a mitsu of america engineer.

this is what would happen if your car came to a dealer, check the code, then go to the medic and see what the sugestions are for that code, aproach it as it needs to be, replace what needs to be, and basically its just done. now if it gets amazingly hard to deal with then more sources are available to solve the problem.

the mitsu shop is not a bad thing nor uncapable.
Ed-