Help I have codes p1171 and p1174 the description is " additive adaptive mixture correction"on both banks. Its a 4.6 v8 with secondary air system. I changed the MAF sensor yesterday and cleared the codes but it back after my drive to work today :-(

Seems to be running a little lumpy too at low revs. I put some seafoam fuel treatment in a few weeks ago and wonder if it has set something off.

Any information i can get will be appreciated. I've been trying to get to the bottom of it for weeks an cant seem to get any information on the issue other than MAF.

 

You need to get an elm 327 Bluetooth adapter and an Android with the Torque app and look at your 02's to see if there are cycling. Although rare, I did have an ECU with a bad set of 02 drivers.

 

Check for air leaks in your intake hoses, I could get mine to throw those as the clamp in the main intake hose started to fail. Letting extra air in at random. Check the throttle body end it would the worse

 

Thanks for the help folks.

When I got home from work today I took off the air intake box and sealed the intake after the MAF sensor. I blew in air from my compressor (at low pressure) and sprayed a bit of washing up liquid and water around the hoses and joints of the intake and secondary air system..... Nothing!

I could just hear a slight hiss coming from where the injectors are sat right under all the gubbins on top of the engine. I managed to direct a bit of spray in that direction and sure enough. I got bubbles from the first slightly visible injector.

So... Im thinking it will need new injector seals? is this a big job? and time wise how long should i be looking at? (I'm pretty good on the old spanners)

I just cant be arsed!

Any input would be appreciated. Thanks all.

 

I'm wondering if the seafoam fuel treatment cleaned those injectors out a little too well ;-)

 

So here is the latest conundrum...

I have replaced my injector seals top and bottom and air intake gasket. new plugs and wires. Cant find any leaks on the air intake. Replaced my MAF sensor and am still pulling codes 1171 and 1174. Does this mean that it is upstream oxygen sensors? surely it is. There is nothing left to change.

HELP...I'm getting desperate here. still running lumpy at low revs. Any information would be appreciated.

 

I doubt it is the O2s. P1171 and P1174 are codes for lean fuel mixture conditions on Bank 1 and Bank 2, and are most often caused by vacuum leaks as you have learned. The reason I doubt it's the O2 is that it would be an unlikely coincidence for the O2 on both sides at the same time. I know you say you can't find any leaks in the intake, but I suggest you try a smoke test.

 

I fought these codes for a while....
had good fuel pressure.
Replaced hoses on intake..
Went to do injector seals, and decided to do injectors as well, valve covergaskets..
end up doing head gaskets and everything
vehicle starts and runs nice....codes return...
check fuel pressure again and like 20psi...
replaced fuel pump...
Running great. 500+ miles since engine work.
Just took a 4WD day trip yesterday and engine ran perfect..great day

 

Hmm, interesting. How would I check fuel pressure?

Im thinking it’s o2’s because I ran sea foam in the fuel and I’ve heard it can kill them. Might be the reason they have gone together ???

i have smog test coming up in September 😭 hope I can sort it before then.