3.2 GSI vectra P0170 and P0173

**fuzzbomUK** · 30th July 2008, 18:02

Hi all,

Just wondering if anyone can help.
My GSI had a faulty MAF so i replaced this, since then i have been getting P0170 and P0173.

P0170 Fuel Trim Malfunction (Bank 1)
P0173 Fuel Trim Malfunction (Bank 2)

I have been unable to hear air leaks of any kind. any other suggestions?

Engine running seems to be ok, though i have noticed it drinks more fuel with the new MAF. was running 26mpg now 20mpg..

Many thanks for your time.

**vectragsi3.2** · 30th July 2008, 18:47

could it be the lambda sensors? i know they have 4 sensors!!!

**fuzzbomUK** · 30th July 2008, 21:29

Many thanks for the quick reply.

Yes to be honest i am afraid it may well be the lambda sensors, they are around £50 a pop.
The other thing i was worried about was it being one of the two cats.

I plan to do spark plugs at some point, then swap the clogged air filter for a piper cross panel filter.
Any other suggestions while im there?

Thanks again,

**vectragsi3.2** · 30th July 2008, 22:02

i had one done for £110 fitted they are about £90 for a new sensor

spark plugs should be done every 40000 miles i was told or 4 years on the 3.2 thats what my garage said to me.

i would get it tech 2'd at a dealers and they will tell you straight away what it is on ly costs about £35

**fuzzbomUK** · 30th July 2008, 22:34

Ive looked on eBay and you can get lambda sensors for about £60 inc postage. im more than happy to do it myself.
Do you happen to know if the pre and post cat lambda sensors are the same?
some cars run 2 the same and others run different ones.

Looking at the service history.. the plugs have never been done lol. its now at 49000.

I have a memoscan U581 this is where i got the 2 codes from.

May as well do plugs and air filter and see what that gets me.

Thanks again,

**vectragsi3.2** · 30th July 2008, 22:46

yes i would do plugs and a change of brake fluid is due around 40000 aswell!

from what people say on here there are only a couple of readers that show up everything not sure if that does!!

there are 4 sensors on the gsi so i was told when mine was done so could be 2 of them but i could be wrong!!! £60 is not a bad price dont know about them being different on pre or post face but are they different on different engines?

**Ste** · 31st July 2008, 10:30

Fitting cheap oxygen sensors can be a false economy, as they may not be as robust. Give VX a call to see how much genuine ones are.

TBH, if the O2 sensors went down, then it is strange that 2 fail at the same time, and wouldn't also get O2 sensor faults flagged too?

**fuzzbomUK** · 31st July 2008, 21:39

Sorry for my ignorance but who is VX? local dealer?

I think both front and rear lambda sensors going down at the exact same time, is a tad weird as well.
I have some hopes on it being the spark plugs and air filter, and this was just showed up by changing the MAF maybe?

My code reader does show o2 sensors (its in the list any way).

On the brake fluid note any idea what DOT fluid it uses?
Local parts dealer said "just put dot 4 in, it will be ok" really didnt inspire me to be honest.

**vectragsi3.2** · 31st July 2008, 22:08

i put dot 5.1 in mine!! going by what you said you could be right and it wont hurt to do that stuff anyway.

**fuzzbomUK** · 3rd August 2008, 22:13

Dear god im staring to think mine was a Friday afternoon built car.
Found the heads on 2 bolts pretty much shredded!! Took nearly 4 hours to do the plugs.
Though it does now pull alot better, while i was there i cleaned out all the oil deposits etc.

Oh and while i think about it, im sure the the area where the plugs are being full of oil isnt correct.
All the bolts on the rocker cover's were only just finger tight.

I have reset the error codes and i shall see how it goes.
Thanks,