Z3 and OBD2 - preparing for emissions etc.

mccalli

Regular Member
Joined
Mar 18, 2018
Points
18
I've got a while yet, but I'd like to know the state of the car for emissions (1.9 1998). MOT isn't until September, but I have a busy few months coming up and so want to plan any time the car might be off road (or, horrors, need to be replaced as cost ineffective to repair. Hopefully not though).

So - I would like to get an OBD2 tool for it. I have an iPhone, which means the adapter has to reasonably new (older ones worked wifi only with iPhones, I definitely want this to be bluetooth not wifi). I'm aware I'll need to get a 20 pin to OBD2 adapter as well.

Not done this before so a few questions to any that have - first off, is there any drawback to simply leaving this setup connected? Second, is there a decent iOS app that would read data for a Z3? And finally, would it be reasonably obvious, like a nice big green tick or red cross, if the emissions were failing?

At the moment I have no reason to believe there's anything wrong with the car. Short of an annoying rattle from the rear left when going over bumps, the car is doing great and travelling about 500 miles a week. However, I don't want to get secure in that believe and then have two weeks to sort everything out in September - would want to know in the run up whether there's anything else I really should know.
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.0i (2007)
The Apps you can use with a ELM327 interface plugged into the cars diagnostic socket(s) will show how sensors are behaving such as fuel trims and exhaust lambda sensors and the Maf. None of the Apps will show you the exhaust CO levels, only an exhaust gas analyzer such as a Gunsons Gas Tester for home use will do that or the garage MOT machine.
Quite a few Apps out there to choose from for use with your phone either Bluetooth or Wifi, some on here use an App called Torque with the ELM 327 interface obtainable from Ebay for a modest price.

Even Lap top software such as BMW INPA will not show you exhaust CO levels but will do all the other sensors that the phone Apps can do.

No harm having it plugged in so you can monitor things whilst driving the car as long as it can maintain its Bluetooth connection. If you have the 16pin OBD2 socket under the steering wheel that will read the engine module only so if you plan on using that go for a short stubby ELM 327 interface so it gives better clearance for your legs.

Whilst we are on about CO levels anyone got the specs for a 1.9's CO level can't find anything on internet quoting the figure used to be listed in Haynes manuals for previous cars I have owned and worked on. Whats the MOT limit for the 1.9 before it gets a fail?
 
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