182 - very low mpg

[griffonu]

Hello guys,

just bought a 2nd hand 182. Had a couple of problems, but I figured nothing too bad. Fixed some.

Now, I've arrived to a tricky one. In short:
- 18 mpg in my daily commute (girlfriend has my old 172 and over the same commute she's averaging 24 mpg so a huge difference)
- a slight lack of 2000 -5000 rpm torque (again, I compare it with the 172)
- car has a decat
- emissions light is on (becaue of the decat)
- I DID change both lambda sensors (pre and post cat) but the mpg is still very very low
- some gas smell when I get out of the car after driving it (seems to run rich?)
- I notice nothing wrong on the temperature, seems to be ok

Normally I would say there's something wrong with the before cat lambda sensor, but since it's been changed, I'm a bit clueless. What else could be causing this super low mpg?

Thanks a bunch!

-VaVaVoum

 

[The Chubby Pirate]

The cat sounds like it may be humped? Also, your girlfriends 172 sounds like its broken as well, they should be averaging mid to early 30's. 24mpg is low.

Have the belts been done recently? Timing out?

 

[TheEvilGiraffe]

^ Danny - decatted !

No wonder it's running rich - 2 lamdas and both still in the pipe ?

I thought one had to be outside to fool it into thinking it was OK ?

Surely if the cat isn't doing anything (as it's not there) the two signals will be the same and it will throw it off ?!

 

[scott.p]

If i'm right in thinking the 2nd lamda will not affect the running of the engine it will reconise that the emissions are high and put the light on but thats it iirc.
I run a decat and still achieve 34mpg

 

[TheEvilGiraffe]

Sounds like it needs taking to someone like Fred/Danny/Dan etc etc.

OP where are you based ?

 

[MRBILLYUK]

24mpg average , if you do alot of town driving sounds about right to me . That's roughly what i used to average on my 172 , and that was from new . Same with my 182 , from new again . I have a very heavy right foot though ;-) . 18mpg sounds a bit low though .

 

[Simon_16v]

18mpg is what my 182 average around a day at Cadwell Park!!

 

[Snake182]

Im averaging 25mpg around town in my 182, with a slightly heavey foot

 

[griffonu]

Sounds like it needs taking to someone like Fred/Danny/Dan etc etc.

OP where are you based ?

Quite far, in Bucharest, Romania

Also, just realised I used US MPG when doing the conversion from l/100 km (what the car shows).

172 (used by gf): 28 mpg in the daily town commute
My 182: 22 mpg, same commute

It's winter, but still something seems fishy. Just wanted to know if there are some other usual culprits for low mpg other than the lambda sensors.
I have an RStuner around the house somewhere. Will take that and put a laptop on it and try to take a look at AFR. It needs a soft done anyway, at some point.

Thanks!

-P

 

[Kazumz]

Hello guys,

just bought a 2nd hand 182. Had a couple of problems, but I figured nothing too bad. Fixed some.

Now, I've arrived to a tricky one. In short:
- 18 mpg in my daily commute (girlfriend has my old 172 and over the same commute she's averaging 24 mpg so a huge difference)
- a slight lack of 2000 -5000 rpm torque (again, I compare it with the 172)
- car has a decat
- emissions light is on (becaue of the decat)
- I DID change both lambda sensors (pre and post cat) but the mpg is still very very low
- some gas smell when I get out of the car after driving it (seems to run rich?)
- I notice nothing wrong on the temperature, seems to be ok

Normally I would say there's something wrong with the before cat lambda sensor, but since it's been changed, I'm a bit clueless. What else could be causing this super low mpg?

Thanks a bunch!

-VaVaVoum

I had a mate mention that the decat actually lost him bhp because of the car registering the emissions and cutting power as it was too high. Something for you to look in to?