P0171 and P1170 codes when at low RPMs or idle

[stockysnail]

I replaced the engine to header gasket (Grimmspeed) and header to overpipe gasket with @ suggested Remflex gasket. As you can see there was definitely a leak which I saw from the vaccuum and soapy water test. I checked for leaks after install and no more leaks.

I had the battery unplugged while doing it so the codes would clear/reset long term trims. The 2nd time driving the car I eventually got the codes after about 20mins of driving. Same P0171 and P1170 codes.

I checked my VVT selonoid plugs for oil leaks but they were clean. I haven't noticed any intake leaks either. The only other thing I can think of is injectors or O2 sensor. I glanced at the port injector area and there's a decent amount of dirt/grim around the injectors but just looks like normal dirt from a 9.5 year old car. I have an appointment with AR Auto Service Feb 17th. Maybe I will pull the port fuel injectors before then to see what they look like.

[blsfrs]

Just for giggles, check for vacuum leaks. I made a smoke machine and tested with starter fluid to be double sure.

[Boccaccio]

+1 on checking for vacuum leaks.

Additionaly,
@stockysnail

Are your hoses securely clamped under the Intake Manifold -->

https://www.ft86club.com/forums/showthread.php?t=109444

EDIT: brain-fart from my side, I just realized stockysnail has the Sprintex supercharged bolted to his engine.

[stockysnail]

I haven't checked for vacuum leaks yet aside from just spraying water and listening near hoses, but I did replace the ignition coils since I didn't do this when I replaced the spark plugs back at 60k miles. I took a quick drive and the trims seemed to be a little different but I'll drive it a few more times to see if it helped. I have an appointment to take my car to the mechanic end of next week so hopefully this fixed it. I'll update this thread once I drive my car a few more times after resetting the ECU to see if the check engine comes back with those codes.

[blsfrs]

Originally Posted by stockysnail

I haven't checked for vacuum leaks yet aside from just spraying water and listening near hoses, but I did replace the ignition coils since I didn't do this when I replaced the spark plugs back at 60k miles. I took a quick drive and the trims seemed to be a little different but I'll drive it a few more times to see if it helped. I have an appointment to take my car to the mechanic end of next week so hopefully this fixed it. I'll update this thread once I drive my car a few more times after resetting the ECU to see if the check engine comes back with those codes.

I don't think spraying water will help find a vacuum leak. You need a fluid that goes boom when ignited. That way if it gets sucked into the engine you will hear a change in engine idle.

[NoHaveMSG]

Originally Posted by blsfrs

Just for giggles, check for vacuum leaks. I made a smoke machine and tested with starter fluid to be double sure.

That is a pretty brilliant setup

How do you like the acusump?

[blsfrs]

Originally Posted by NoHaveMSG

That is a pretty brilliant setup

How do you like the acusump?

I installed the Accusump on the recommendation of Element Tuning when Phil built my engine. I'm not sure that I actually "need" it for HPDE 1-2. It may help when/if I get faster.



I found it a bit tricky figuring out how much oil is in the accumulator vs the pan until a buddy told me about Boyle's Law: P1V1=P2V2 which has do to with the volume of air at a given pressure. You do have to carefully monitor your oil level in your engine vs what's in the accusump. At idle, with the valve open, the level is probably 1-1.5 quarts over full. The higher the rpm and OP the more oil that goes to the accumulator. Some argue that pressure needed to fill the accusump might take away oil from the engine.


I use a PTO cable to open and close the valve. I had problems with 3 different electric ones. I just have to remember to open and close the dang thing when entering and exiting the track.

[stockysnail]

Last weekend I installed new ignition coils and reset the ECU. I didn't get the engine code until today (5 days later) which was longer than previously. My car has 90k miles on it so I figured I should replace them anyway since there have been a couple revisions on the coils and never replaced them (bought my car new in 2012). Coincidentally today was finally the day my appointment at AR Auto Service happened. They called and said they found 2 vacuum leaks, one in the supercharger gasket to the manifold and one in a hose from the supercharger under the manifold (I think that's what they said). They will order parts (hopefully easy to find for them) then do the work when they arrive. I'll update this thread once that step is fixed.

[haloterence]

Had something similar with the P0171 and P1170 codes. It only happens when the engine was cold under 105 degrees. Ltft and Stfr stabilize after the engine warms up. I read somewhere that it could be the intake manifold gasket sealing itself when heated. Upon replacing the intake manifold gasket I found out that there was also one missing fuel injector seal Number: 16608KA000. I guess the careless mechanic that did the J02 recall was dumb enough to leave one out.

[stockysnail]

A little but of an update.

The mechanic, AR Auto Service, has been working on my car on and off for 6 weeks (multiple times they were waiting for parts and tools). They found multiple vacuum leaks and replaced the supercharger gasket, various hoses. They found a small leak in the headers that they had the welds fixed. Cleaned and put new seals on all the fuel injectors. Still getting the lean code. Hopefully they figure it out. I gave them the info on the person that tuned the car but that wouldn't make sense as I've had the same tune running for 7 or 8 years.

I replaced the ignition coils when they I took the car back for a week when they were waiting on the supercharger gasket part.

I didn't change anything on the car for months prior to when I started getting the lean code.

[bcj]

Filter in the fuel tank/pump?

[Boccaccio]

Perhaps checking if the EVAP system is leak free? That might also cause a lean code.

Food for thought, I spotted this on the Scion Xa/Xb forum:

https://www.scionlife.com/forums/sci...e-over-124130/

[kev0]

Originally Posted by stockysnail

A little but of an update.

The mechanic, AR Auto Service, has been working on my car on and off for 6 weeks (multiple times they were waiting for parts and tools). They found multiple vacuum leaks and replaced the supercharger gasket, various hoses. They found a small leak in the headers that they had the welds fixed. Cleaned and put new seals on all the fuel injectors. Still getting the lean code. Hopefully they figure it out. I gave them the info on the person that tuned the car but that wouldn't make sense as I've had the same tune running for 7 or 8 years.

I replaced the ignition coils when they I took the car back for a week when they were waiting on the supercharger gasket part.

I didn't change anything on the car for months prior to when I started getting the lean code.

I am super curious as to what the issue is once you find it. I am super invested into this.

[stockysnail]

I may get my car back next week. I'll give an update once I get it back. It's been 3 months without a car which sucks. Good thing I have a motorcycle as my backup transportation.