2sz-fe poor fuel economy

[pwuser162374518264]

Recently bought 1999 convert vitz which gives me 9 km/ l in city without ac then went to mechanic he cleaned the spark plugs ands service throttle body changed injectors, fuel pump and filters but dsnt work then went to electrician computer says airflow error so changed the map sensor but the result is same
Experts plz help me

[asgharpwr]

Please check O2 sensor performance, long fuel trims shouldn't be above +10. Lastly check engine compression.

[helper_learner]

Tell your city so can guide regarding the workshop hit and trial is not a proper way.

It is of no good to change the parts that are properly working.

[pwuser162374518264]

Brother I m from Peshawar

[pwuser162374518264]

How to check engine compression?

[pwuser162374518264]

From Peshawar

[helper_learner]

Engine compression is checked using compression testing kit,

[helper_learner]

From Peshawar

@horticulturalist, Kindly help this brother as you are from same city

[asgharpwr]

Please visit gul nawaz ustad workshop near tambano mor, gul nawaz himself dsnt wrok bt he has a guy name zubair ustad his no is 03159560461. Vist him and tell the whole story. On Sunday thy are off. Where in peshawar? Which grade engine oil and tire size ur using?

By the way u cant get more than 11 to 12km/l on peshawar roads and that also if you drive very carefully and dont rive too much.

[horticulturalist]

Nawaz ustaad in which centre? Subhan or nawab?

[horticulturalist]

@asgharpwr is right... You can't get more than 12kmpl. So for adding the 3 to your 9 kmpl:

change engine oil grade to a recommended one (check PW forums for that),

tyre pressure to the recommended,

tyre size shouldn't be much more than recommended,

change spark plugs to the better irridium tip ones,

service throttle body,

service fuel filter,

check injectors,

clean the o2 sensors and cat (not necessary unless do it from a good mechanic),

check fuel trims by obd2 tool (if you need that scanning, i'll do it for you for free).

Lastly, if nothing helps, do a compression test.

[Hassan1991]

Never clean O2 sensor. Both things should be replaced when needed.

[asgharpwr]

He has own workshop from city side when you cross tehkal stop then near to runway end (tambano mor) thr cme a small street on left side.

[pwuser162374518264]

Don’t know which grade used previous owner I put 1030 havoline and tyres size is 165 70 14

[pwuser162374518264]

Yesterday when I came home from a 50 km drive and parked the car engine was not stable I think there is idling problem

[horticulturalist]

That need to be diagnosed bro... Get opinions from a mechanic or two

[horticulturalist]

10-30 is a fine mobiloil, if your car isn't decreasing oil, or there is no smoke from the exhaust, then don't change this grade

[horticulturalist]

May be I have visited this place... Its a mechanics yard, clay ground.

[asgharpwr]

Oil grade is OK.
Factory fitted tire size is 155/80 R13 while the recommended alternative could be
165/75 R13,
175/70R13, or
175/65R14

[pwuser162374518264]

Tyres are a bit weak I want to replace them.. I think 175 width will effect fuel efficiency