MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Chris 180SX on March 7, 2010, 12:05

Title: Where is OBD port?
Post by: Chris 180SX on March 7, 2010, 12:05
Sorry for the lame topic, but I did search - I have just got a CEL and want to read it (I have a reader) but can't find the port?
Title: Re: Where is OBD port?
Post by: uktotty on March 7, 2010, 12:07
Under dash on right of steering wheel
Title: Re: Where is OBD port?
Post by: Wabbitkilla on March 7, 2010, 12:29
Just feel along the bottom of the dash to the right of the steering column and you will find it   s:wink: :wink: s:wink:
Title: Re: Where is OBD port?
Post by: Chris 180SX on March 7, 2010, 12:58
Thanks guys!  Feel so stupid now!!!!

It was a 0141, which I believe is the post cat O2   s:( :( s:(    What a lovely day for a car problem!!  I should be OK to drive it till I sort it, shouldn't I?  Guess I'm going to get stung for a few quid...
Title: Re: Where is OBD port?
Post by: mrzwei on March 7, 2010, 14:48
The sensor relays a message to the ECU which may then modify the mixture, or in this case, may modify it because there is no message. Don't think there will be a problem driving it and there are some cost effective solutions out there. This of course could be bollocks, just my understanding, but there will be more informed opinions to follow.
Title: Re: Where is OBD port?
Post by: StuM on March 7, 2010, 16:37
Pretty sure that the signals for the post-Cat sensor (the one that throws a P0141) aren't used by the ECU to adjust mixture.

As I understand it, the sensor only reads the emissions output properly when it is warm.  As it is cold first thing (for a couple of seconds) after a start, there is a heater circuit as part of the sensor, pre-warming it and allowing accurate reading.

This heater circuit would seem to be the most common source of failure - even though it has failed, the rest of the sensor works ok.  So, options are:

1) Fit a resistor into the heater wiring so that the car *thinks* it's working which fools it into not throwing the code, or
2) Fit a new O2 sensor - best price I've found for an original part is £80ish.

Short answer, I think that you are fine to keep using the car.
Title: Re: Where is OBD port?
Post by: muffdan on March 7, 2010, 17:08
that's right, the post cat sensor isn't used in the running of the engine and it's perfectly safe to drive the car with it malfunctioning.
Title: Re: Where is OBD port?
Post by: uktotty on March 7, 2010, 18:51
The resistor fix is pennies mate, easy to remove that 141
Title: Re: Where is OBD port?
Post by: Chris 180SX on March 7, 2010, 21:00
Excellent, thanks so much guys, feel a lot better than when it first flashed up this sunny morn!    s:D :D s:D   I will look at replacing maybe when I do my precats soon...
Title: Re: Where is OBD port?
Post by: nathanMR2 on March 7, 2010, 21:11
Ive just replaced mine today, no more CEL's so far and ive done 50miles+

I paid a shade under £60 delivered for a Denso post cat sensor (with lead and plug) so a direct replacement.

PM me if you want the details
Title: Re: Where is OBD port?
Post by: Anonymous on March 7, 2010, 22:14
Quote from: "nathanMR2"Ive just replaced mine today, no more CEL's so far and ive done 50miles+

I paid a shade under £60 delivered for a Denso post cat sensor (with lead and plug) so a direct replacement.

PM me if you want the details

Why not put the details here and let everyone know.  l viewtopic.php?f=11&t=19412 (http://www.mr2roc.org/phpBB3/viewtopic.php?f=11&t=19412) l
Title: Re: Where is OBD port?
Post by: nathanMR2 on March 7, 2010, 22:16
I will do mate.

I just wanted to get a few more miles on it before putting it out to the masses
Title: Re: Where is OBD port?
Post by: Chris 180SX on March 8, 2010, 11:30
That would be great, cheers, bit cheaper than I thought too!   s:) :) s:)
Title: Re: Where is OBD port?
Post by: nathanMR2 on March 8, 2010, 14:17
Let me do some digging and ill see if i can get some sorted for the club at a better price
Title: Re: Where is OBD port?
Post by: uktotty on March 8, 2010, 14:37
Cheers Nathan, looks like I need TWO  s:( :( s:(
Title: Re: Where is OBD port?
Post by: Mad Matt on March 8, 2010, 14:42
OK, I know this isn't a group buy thread, but I've got the notorious code too. I know it's not serious, but it is irritating so I'd be interested too.
Title: Re: Where is OBD port?
Post by: nathanMR2 on March 8, 2010, 20:25
Please see

 l viewtopic.php?f=36&t=28730 (http://www.mr2roc.org/phpBB3/viewtopic.php?f=36&t=28730) l