Keep getting a p0174 (lean right bank) code
#1
Keep getting a p0174 (lean right bank) code
For about a month I've been getting a p0174 code (sometimes it will go restricted performance for a short time as well). Comes on when coasting or light on the gas. Today it did it while I pulled over to take a phone call and engine slightly stumbled like it had a miss for a couple of revolutions. I've reset the codes and it is good for a few hundred miles before coming back. It is our 03 XJR. Any thoughts on what to look for first. I would think a bad maf or vac leak would likey throw codes for both sides right? Oh and which bank is the right when looking from the front of the car. My dislexia gets me confused on that one all the time. Thanks!
#2
#3
That DTC lists the following possible causes,
Engine misfire
air intake leak between MAF and throttle (THIS IS MOST LIKELY)
fuel filter/system blockage
fuel injector blockage
fuel pressure regulator failure (low fuel pressure)
HO2S harness condition fault
Exhaust leak before CAT
ECM receiving incorrect signal from ECTS, MAF, IATS, TPS.
My money is on an induction leak, it effects both banks. Check the induction tube for cracks around the corrugated section, the seals on top and underneath the throttle body, the MAF connector onto the induction tube all can and do leak leading to DTC. Give the MAF a blast with electrical contact cleaner (in a can) and start from there....
Engine misfire
air intake leak between MAF and throttle (THIS IS MOST LIKELY)
fuel filter/system blockage
fuel injector blockage
fuel pressure regulator failure (low fuel pressure)
HO2S harness condition fault
Exhaust leak before CAT
ECM receiving incorrect signal from ECTS, MAF, IATS, TPS.
My money is on an induction leak, it effects both banks. Check the induction tube for cracks around the corrugated section, the seals on top and underneath the throttle body, the MAF connector onto the induction tube all can and do leak leading to DTC. Give the MAF a blast with electrical contact cleaner (in a can) and start from there....
The following users liked this post:
Don B (03-04-2018)
#4
My money is on an induction leak, it effects both banks. Check the induction tube for cracks around the corrugated section, the seals on top and underneath the throttle body, the MAF connector onto the induction tube all can and do leak leading to DTC. Give the MAF a blast with electrical contact cleaner (in a can) and start from there....
#5
#6
The following users liked this post:
Don B (03-04-2018)
#7
Couldn't figure out how to screen shot the fuel trims but I also have a code now for p01533 (o2 sensor slow to respond) so I am wondering if that might be the issue and it just didn't throw a code til now. The snorkle was on good and tight no cracks etc. I didt pull it off and reinstalled just to be safe. Don't have a place to work on it at the moment. TVR is in the process of new rear brake calipers and rotors which will probably take another week. Imagine the Jag inboard IRS in a tube frame chassis and you get the picture. Not much fun at all!
Trending Topics
#8
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
The following 2 users liked this post by NBCat:
Don B (03-04-2018),
TreVoRTasmin (03-01-2018)
#9
#10
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
The following 2 users liked this post by NBCat:
Don B (03-04-2018),
TreVoRTasmin (03-01-2018)
#11
#12
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
If the electrical connections to the oxygen sensor are good, the next thing is to check the fuel pressure. The P0171 and P0174 DTCs can also be caused by low fuel pressure, which in turn may also cause the 'slow response' of the upstream oxygen sensor(s).
Check the Workshop Manual for correct fuel pressure at idle and under load.
Check the Workshop Manual for correct fuel pressure at idle and under load.
The following 2 users liked this post by NBCat:
Don B (03-04-2018),
TreVoRTasmin (03-01-2018)
#13
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
The following 2 users liked this post by NBCat:
Don B (03-04-2018),
TreVoRTasmin (03-01-2018)
#14
Thanks NB, it will probably be a few weeks til I can get at it as I don't got the garage space with my TVR being on jackstands at the moment. Plus I need to scronge up a gauge as I don't think my bike air pump would work real well. Both pumps and the pigtail were replaced within 20k or so but of course new parts do fail as well. Put some Techron in to clean the injectors for the time being. Got lots of driving to find snow coming in the next couple weeks.
#15
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
You could use a gauge like this one:
https://www.ebay.com/itm/Professiona...FYPUyv&vxp=mtr
If the fuel pressure is within specification, the upstream oxygen sensor (before the catalyst) is probably the cause of slow response.
https://www.ebay.com/itm/Professiona...FYPUyv&vxp=mtr
If the fuel pressure is within specification, the upstream oxygen sensor (before the catalyst) is probably the cause of slow response.
#16
You could use a gauge like this one:
https://www.ebay.com/itm/Professiona...FYPUyv&vxp=mtr
If the fuel pressure is within specification, the upstream oxygen sensor (before the catalyst) is probably the cause of slow response.
https://www.ebay.com/itm/Professiona...FYPUyv&vxp=mtr
If the fuel pressure is within specification, the upstream oxygen sensor (before the catalyst) is probably the cause of slow response.
#17
Join Date: Jan 2012
Location: Newport Beach, California
Posts: 5,668
Received 2,676 Likes
on
1,836 Posts
#18
The following users liked this post:
Don B (03-04-2018)
#19
Knowing the common issues with the X308. I would be looking to replace that O2 sensor and the fuel pumps. The exact O2 sensor (direct fit same Bosch) is available outside of the dealer network .. so get the exact replacement.
I had some strange operation prior to me understanding I was getting an intermittent fuel pump failure. I give my independent a lot of work -- they install my sourced parts. I did two OE pumps and attached filters and replaced the main fuel filter. The main filter is a GM filter .. get a good one (the last a long time).
The restricted performance could be another thing all together ..... if the engine stumbles and the output from the alternator drops below the threshold ... even for an instant -- you will get the RP. Especially if you are idling coming to a stop with the brake lights on.
I was getting RP as a coasted to a light .. and also while sitting at a light a while back. I almost sent the Tbody away. The battery showed no signs of weakness ... it was a middle aged battery (4 years) -- I replaced it anyway and it been two years now. The battery must be perfect on an aging X308 .. any strange flux in the voltage .. from wipers/AC compressors .. throws them off.
I had some strange operation prior to me understanding I was getting an intermittent fuel pump failure. I give my independent a lot of work -- they install my sourced parts. I did two OE pumps and attached filters and replaced the main fuel filter. The main filter is a GM filter .. get a good one (the last a long time).
The restricted performance could be another thing all together ..... if the engine stumbles and the output from the alternator drops below the threshold ... even for an instant -- you will get the RP. Especially if you are idling coming to a stop with the brake lights on.
I was getting RP as a coasted to a light .. and also while sitting at a light a while back. I almost sent the Tbody away. The battery showed no signs of weakness ... it was a middle aged battery (4 years) -- I replaced it anyway and it been two years now. The battery must be perfect on an aging X308 .. any strange flux in the voltage .. from wipers/AC compressors .. throws them off.
#20
The following users liked this post:
Don B (03-04-2018)