SSSean

Suggestions please.. I am currently getting a P0171 within 10 miles of resetting the SES..

Prior to that I was getting P0430 and P1416.. I replaced 3 O2 sensors both pre-cats and the Driver side Post Cat. I also replaced the check-valve on Drivers side. I also cleaned the MAF sensor. It’s a SLP 1997 SS w/ 66K miles..

Last week I went to remove and clean the driver’s side check-valve before a road trip and found it quite tight and decided to just try and clean the check-valve while on the engine. I removed the hose and sprayed Sea-Foam in the Check-Valve while the engine was running till she started to smoke hard and shut her down for 10 minutes… Then went out on the highway and found the light had shut itself off and the engine seemed to run a little bit stronger then normal. In the past when in a high gear at low RPM the engine would seem to buck a little bit. Say in 6th gear doing 50 mph and hit the gas she would stumble a little.. This time she just accelerated very smoothly. About 30 miles into my highway trip dam light came back on.. but she ran fine all the way down to my destination about a 100 miles..

On my way home she was running a little rougher then on the way there.. At one point I got the blinking SES light and code for intermittent cylinders firing “I am at work and forget the exact code” then cleared up.. I stopped at Autozone to read/clear codes..

Again the P0171 came back on within 10 miles of resetting.. I am with out an inspection sticker and need to get this car inspected soon..

I am looking for some suggestions on the P0171 SES light…

Question about emissions inspection.. If I Sea-Foam the engine to get the SES light off then go in for an inspection will I pass with P0171 code stored in the memory?

Thanks for reading..

Injuneer

We would prefer that you post a topic on only 1 forum. This is the one I will leave open.

P0171 is telling you there is a lean condition on Bank 1. That's what you need to track down. An exhaust leak before the O2 sensor is a possibility, and that leak could be through the check valve. Or maybe the gross amount of Sea Foam has contaminated the O2 sensor. A little bit of Sea Foam through the engine is one thing. Pouring it directly into the exhaust, where it starts to burn in the exhaust could cause problems with the O2 sensort or the cat.

The thing that seems to be a contradiction is that you had P1416, which is for the Bank 2 AIR system, but you replace the drivers side/Bank 1 check valve. And within an apparently short period of time you are finding a new valve getting "tight".

SSSean

Sorry about the dual post.. I went ahead and replaced the drivers side check valve went and reset the SES.. Came back on in less then 5 miles.. I looked for an exhaust leak and could not find one.. Looked for leaking vacuum lines and again nothing very obvious.. Any thoughts?

Injuneer

You indicated the SES light was flashing and you had a code for misfires. Do you feel the engine misfiring? That could cause a false lean condition.

Next check the injectors. Swap them side-to-side and see if the lean condition follows them to the other side.

Is your engine modified in any way - headers? If you have headers, did you use O2 harness extensions?

SSSean

I did feel the misfire occur for a short while on my way home last week while on the highway.. it went away shortly there after..

I have since reset the SES condition 2x only to get the P0171 code again..

I put a stethoscope on each injector the “lifter looking” components sticking out of the inake and heard a pulsating tap sound from each of them.. I thought that was an indicator that they were working??

That sounds like a good idea to swap them left to right to see if the condition follows.. They look easy remove.. Thanks for the suggestion..

The engine is a stock SLP with the exception of a loudmouth exhaust the original owner put on at around 10K miles..

Injuneer

If you hear a clicking, the injector is pulsing and opening. Problem could be it is plugged with dirt and not flowing fuel when it opens.

SSSean

Thanks for the information.. While I have the injectors out seems like a good idea to spray them down with a cleaner or something.. Any suggestions on cleaning are gladly welcomed..

Thanks,

Sean

SSSean

Just a thought.. would unplugging each injector one at a time at idle prompt a properly functioning injector to effect the idle/RPM or would this only be valid in a drivability test?

SSSean

So far so good.. 20 miles and no light I hope it stays that way and will keep you posted.. I pulled the injectors and using a syringe put marvels mystery oil in nipple and using an external power source AC/DC convertor 7.6 VDC activate the solenoid a few times to ensure the marvels seeped through the injector and let them sit overnight.. In the AM I took a length of tuning and filled with carbcleaner attached one end to 50 LBS of compressed air and the other to the injector inlet while my son pulsed the solenoid with the external power source.. Each injector had a nice spray pattern.. Put her all back together swapping injectors left to right.. One leaking 0 ring and which I picked up at Autozone while resetting the code.. Drove around a little bit noticed marginal gain in drivability but no light.. Where in the past would come on within a few miles.. Hoping it stays off for good..

SSSean

spoke to soon... 32 miles lights on back to Autozone tomorrow..

SSSean

Performance is slightly better and 0 driveability issues.. But same P0171 code after a trip to Autozone to borrow the code reader..

Any suggestions on the next step are very welcome..

SSSean

In addition to the P0171 code I also got a P1416 indicator.. For lack of things to try I switched O2 sensors side to side cleared codes filled with a fresh tank of Sunoco 93 Octane and took a road trip of about 200 miles.. Today I got the infamous P0171.. Car run strong and I am at a loss.. For the heck of it I changed the stock K&N filter with a paper style to see if K&N could be allowing to much air if thats even possible... Really running out of suggestions and hope someone has something else to look into as I doubt downgrading the airfilter will help... Thanks for looking..

Injuneer

Might be time to do a data log, to see what the long term fuel corrections are doing. The code sets when the LT fuel trims approach the upper limit of their ability to add fuel. You need to see if the problem truly is only on the driver's side. If only the driver's side LT fuel trims are elevated, its a problem affecting only that side. If the passenger side LT fuel trims are also elevated, but not enough to set P0174, it would indicate a problem that is affecting both banks.

A K&N will not "allow too much air"..... the change in air flow at part throttle is not very much, and the MAF sensor would pick up that added air flow, and the PCM would add the required fuel based on the increased air flow. But you don't see much difference in flow at part throttle.... only at WOT/max RPM. Ay chance you are over-oiling the K&N and getting oil in the MAF?

SSSean

Thanks for the input Fred.. Light came on at about 35 miles and shut off at around 50 miles… You have me thinking about over oiling the K&N.. I did spray some more oil on it a couple of weeks ago just thinking it would “catch more stuff” while I was troubleshooting these codes… The code was generated with the paper filter on but turned itself off at around 50 miles.. I thought I read that as long as the SES light is not on there are no issues at that time but previously detected codes ares stored in system until deleted.. I really need to get this thing inspected and am going run it for the rest of the week and if the lights stay off take it in for an inspection on Sat… After that I will clean the MAF again and clear the code and see what happens.. If I get the light I am gonna have to find someone who can perform the data log.. Thanks for your help.. I checked out your page nice ride you have there..

Injuneer

The inactive codes are "stored" for a specific number of "drive cycles". If the problem does not happen again during the specific number of drive cycles, the code will self clear from memory.