Q about MAP and Baro readings related to error code P0069

[j-modig]

Hi,

New user here, trying to troubleshoot an error code on my son's 2007 speed 3 (or MPS 3 as they are called here in Sweden).

Code is P0069 according to Dashhawk:


I can display readings for MAP and Baro. When turning on ignition (without starting engine) they read 70 and 98 kPa respectively. I guess, at least in theory, they should be the same = ambient atmospheric pressure (which happens to be almost exactly 98 kPa).




When starting and driving MAP drops as vacuum builds in the intake while Baro is pinned at 98. MAP reading seems very consistent with driving, only the scale seems offset.
Car runs perfect though. No hesitation when accelerating and no rough idle.

A crappy video giving some gas in third. Hard to see but you see MAP rising and briefly running higher than Baro (=boost).

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Any input suggestions or speculations welcome

/Johan

 

[Raider]

What modifications? OEM map or tuned?

 

[Enki]

This is either an electrical issue with the MAP sensor (assuming you really are around 300m above sea level as suggested by your confirmation that baro is 98 kpa), it has a non stock MAP sensor, or it has a custom tune on it that is set up for a higher range MAP sensor than what the tune is expecting. Sorry but I can't be bothered to do the math on this to figure out which one at this time.

The MAP sensor is on the left hand side of the intake manifold somewhat under the runners; if you check the model number on that and search for it, it should tell you the range in BAR for the sensor.

I think stock is 2.5 BAR so if not that, probably aftermarket and swapping it out with stock or tuning for it will resolve your issue.

 

[j-modig]

Thanks @Raider and @Enki for input.

I don´t have all the details on the car since mods were made by the original owner. It has a Hypertech tune and some minor mods (short ram air intake, K&N cone style air filter, catch tank, some exhaust work). Stock turbo and tmic. It came with a dyno printout for 292 hp at the wheels. It's been running flawlessly since we bought it three years ago with only regular servicing (and more or less since new according to previous/second owner). Still runs great but code returns after clearing.

Recent tinkering include new plugs (Denso itv22), cleaned and re-oiled air filter, cleaned MAF-sensor.

My guess is that the MAP-sensor is original and needs replacing (with a new stock one). I'll check if I can get a good view. Some harness bits in the way when I tried last night.

I'm actually not att 300 m above sea level, but 98 kPa (Baro reading) was indeed in line with local weather service observations .

Cheers
/Johan

 

[Raider]

1) remove the Hyperfail. Awful thing long since discontinued.
2) you do not have the mods to need step colder plugs.
3) for MAP sensors, oem is the only way. Aftermarket have been proven to be junk.

 

[j-modig]

@Raider

1. OK , noted. Found some old threads confirming that (with the odd exception). Another tune likely won't happen (old car by now) so going stock seems the way to go for increased life expectancy as a fun daily driver.
2. OK, got those on recommendation but I'll look into going stock. What actual problems could I be looking at?
3. Got it. Will order one as local Mazda dealer/shop didn't have one to sell me (BOSCH any good?)

/Johan

 

[j-modig]

Short follow up for the archive with good and bad news.

Changed the MAPsensor and it seems to work OK. Turning ignition on without cranking over MAP and Baro are (almost) the same. Also the P0069 code hasn't returned (and no other DTC).


Bad news is that the car failed emissions inspection. It has high CO, both at idle and at 2500 rpm, and high lambda (1.35). Don't know about the CO but high lambda would indicate a lean condition right? (I'll poke around the Dashhawk this weekend)

So there is something else wrong as well.
One suspicion is crank case ventilation since the old MAP looked quite oily when pulled out of the intake manifold. Car has a Saikou Michi catchtank installed but I am not sure if it's been drained often enough...

I'll have a look for vacuum leaks as well but since I'm no mechanic I'll probably just leave it at a garage.to get it fixed properly.

cheers
/J

 

[L337TurboZ]

Did you remove the old tune and go to stock?

 

[j-modig]

Did you remove the old tune and go to stock?

Nope. MAP-sensor was stock so figured it would be OK to keep the tune since I replaced sensor with an identical Bosch unit.
EDIT: pic of old sensor with wonky readings.

/J

 

[Duey1083]

The oil, as you pointed out, is likely from your PCV valve.

Mine was oily when I replaced mine as well. I wouldn't be too worried if the car isn't using a lot of oil and your turbo isn't smoking.

 

[L337TurboZ]

Nope. MAP-sensor was stock so figured it would be OK to keep the tune since I replaced sensor with an identical Bosch unit.
EDIT: pic of old sensor with wonky readings.
View attachment 20865
/J

Consider going back to then factory tune for emissions testing. Your current tune can throw off what the car should be doing with emissions

 

[j-modig]

Consider going back to then factory tune for emissions testing. Your current tune can throw off what the car should be doing with emissions

Yes, I'm aware of that and might very well end up going stock (as much as possible).

But at the same time, the car has been running flawlessly in this exact setup for 10+ years and passed yearly tests without a problem. So something is not right.

Anyways, I did a hunt for vacuum leaks without success. Sprayed starter gas at vacuum hoses, clamps and connections while idling but could not detect any rpm fluctuations whatsoever. Maybe because it was lawn mower spray according to can

I will follow up once I get this sorted.

/J

 

[j-modig]

OK, new update.

Left the car with a local garage and they came back saying that lambda/O2 sensor is bad and need replacement. Doesn't sound unlikely given the car's mileage and hopefully it will return to normal operation. They had the part on backorder so will have to leave the car with them again to do the actual work.

I'm a bit concerned though. On the Dashhawk I only have one active O2 sensor reading (B1 S2), the other three read N/A (I get that there is no Bank 2).

The fact that B1 S1 isn't reading anything could be a confirmation that it is bad, but since the car runs fine I'm worried it might be related to mods by previous owners and that "fixing" it could lead to more problems. If it does, going back to factory tune will be the way to sort it I guess. Unfortunately I don't know it it's been like this previously as I only just started tinkering with it.

EDIT: Dug out a mods summary from first owner and it seems second cat is stripped out and replaced with a 2.75" pipe. Since there are no other details, I guess first cat on downpipe is the stock one.

Note to self: don't get a modded car without the right skills

/J