carbizman

hi. new to the forum name is Carlos from NJ. i have a 1998 Lexus es300 with 300,000 +. it all started with an 8 plug change and new wires. then came the p0171 and failed nj inspection.
i have replaced what were new intake gaskets with more new intake gaskets. i replaced a/r sensor for bank 1 sensor 1. replaced pcv valve. replaced old vacuum lines. everything is new from amazon yet, i still get p0171 code and nothing else.
the car starts and runs fine. as the coolant warms up the car starts to run rough. its has a "lope sound" to it. sounds like she is going to shut off, but never does.
as for its performance. it is great a regular rocket ship but, come to a traffic light and it drops to 750 rpm and watch the needle go up and down. light turns green, rocket ship again.
the classic p0171 is a vacuum leak i did a propane test by opening up the bottle and taking it to all the vacuum hoses. the engine never raced. reisistance test on fuel injectors is good and in spec.

so help what now?
thanks.
bizmanracing

MedicalDoc

How is your MAF? Any exhaust leaks?

carbizman

thanks for the reply. there are no codes on the MAF sensor. i did remove it and cleaned it as completely as i could. i used the product called mass airflow cleaner, it comes in a gray can. it looks and smells alot like brake clean. still codes returned as p0171. as for exhaust leaks to my ear none. but, my wife says i'm hard of hearing from one to many trips down the quarter mile.

so based on my answer any ideas?

pushtree

I have the same problem right now on my 99 RX300. There *was* an exhaust leak - the leaky section was replaced but the CEL kept throwing off the 0171 code. Checked again, for any vacuum leaks, cleaned the MAF sensor, which is a couple of years old. Next step is to replace it - found one on Amazon for around $20

carbizman

thanks for the reply

no thats not my problem "i think" when i think of exhaust leaks i think of noise. my car is very quiet. but, for the record i gave up and sent it to the local garage. it wasn;t my idea. my wife said that i played with that car long enough take to a pro. well, i got a call from that garage said the problem was the lower intake gasket. they said it was craked. that gasket was the second new gasket that i replaced. its costing me 714 dollars. i haven't picked up the car yet. i will do that on Monday next. i just can't believe that is the problem. i poured a ton of propane in that area and the engine never raced. i told the shop that they need to drive the car more to ensure the problem is solved. they said they would. we will see. my gut lets me the shop feels problem solved and the car is just sitting there waiting for me to set the p0171. code.
therefore....
my question is how do you handle a garage that didn't fix my problem but did take my money and now will want more. how do you address that they made a repair that wasn't needed.

Doublebase