Thanks for reading my Post my Hummer H3 2007 3.7l I-5 with 88000 M on odometer runs like crap lately for last 4 days today i just bought a code scanner to find that it came up with 4 codes which are(P0171,P1133,P0133,P0128) starting by thermostat code P0128 was for stuck open thermostat (P0128 ECT below thermostat reg temp) any way i bought a new thermostat and the temp is back to 1/2 to nearly 3/4 and i erased the codes after a 10 mile trip same fuel in tank the MIL come back showing only 3 codes on scanner

P0171 engine too lean
P0133 O2 sensor circuit slow response B1 S 1
P1133 heated oxygen sensor HO2S insufficient switching B1 S1

here are the freeze frame records

DTC P0171

Fuel SYS1 cl

Fuel SYS2 N.A

Load PCT calculated load value 18,0%

ETC engine coolant temp 86 C or 187 F

Short term fuel 1,6%

Long term fuel 24,2 %

Map 29 KPA

RPM 601 RPM

VSS Vehicle speed 0

spark advance ignition timing advance 10

IAT intake air temp 57 C

MAF 3.00 g/s

TP 12.2 %

Air Stat off


please help me out i love this rig and i want to keep it till i find a good lo millage V8 alpha or plan on keeping mine till 200000M

FYI car use is just for off road

TB cleaned every 6 months -air filter changed with new one - EGR valve cleaned it was full carbon - filter is changed every oil change - used oil 10 w 30 AC Delco U.S.A -Coolant changed and radiator flushed at 80000m used DEX coolant - spark plugs changed with the same OEM model at 80000M - trany oil and filter changed every 30000M with dexron VI - MAF is cleaned with Carburetor Cleaner due to no MAF cleaner spray avilable here

Fuel type Super unleaded

please help me thanks in advance what do i have to do to get it back to normal

now i see drop rpm at stops and accelaration is really crap fuel millage
what to tell 27L For every 100 KM no AC on
car temp is between 1/2 to 3/4 at high speed out city its even 1 mark below 1/2 and outside temp is 20 C

 

any one?

 

31 views no response

 

I would hardly cause your codes urgent.

Couple things, you have an 07 I5?? , so you are supposed to be using 5W-30 oil and the I5s do NOT have an EGR valve (they use VVT instead).

You have a bad O2 sensor, it is slow to respond and faulty causing your P0171 lean code during initial start up strategies. Change the O2 sensor.

 

from now on i will use 5W-30 thanks man

do i have to change the heated oxygen (HO2S)sensor only ?

or change Both HO2S and the other one near catalytic converter too?

about the EGR sorry my mstake i don't know what is the name of this valve? it was really dirty carbon in the valve

 

According to your codes, it is the front sensor, so I would try that one first. When you are looking for it on line, it is O2 sensor 1.

You cleaned the air injection check valve, part of the secondary air injection reaction system. That's what makes the faint fan like blowing noise about 1-2 seconds after you first start up the I5s when they are cold, and only stays on a very short while.

 

thanks a lot i appreciate your kind response and great information help tomorrow i will change the HO2S and update the car status after the change .

 

Good thread.

Chris

 

today i changed the HO2S the car acceleration is much better now but MIL is back just after i got on road an driving like hell around 3000rpm to 5000rpm to test the performance of the car checked the code is reading P0171 what to do?
the MAF live data at 600 to 750 rpm was 20 and it just jumps to 100 or much more at higher RPM is that correct? any help suggested?

long fuel term is 20% is this normal? the authorized PC person told me its too much .

if i put freeze frame info will it help to Diagnose the problem?

 

If your O2 sensor was not THE cause, search P0171 here

https://www.hummerforums.com/forum/h...g-light-28003/