singleslam

Ok, let me start of saying i'm not the most experienced mechanic, at only the age of 23. But i've never seen anything like the problem i'm experiencing, and generally stick to the Honda side of things. So, after being put thru the ringer with this car (03 rx300) i've finally broke down and decided to ask for help, before I let the dealer take over.

Let me explain what happened here from the beginning.

The owner of the vehicle contacted me to look at this car due to blue smoke coming out of the exhaust. Upon inspection, I found the whole motor was full of sludge, lack of oil changes. Pulled the motor, overhauled it, at the machine shop I work for. There was no other option, from oil pan to heads, the engine was full of sludge. Burning a quart of oil every 60 miles. Valve seals were smoked, piston rings were smoked, had 2 burnt exhaust valves in cylinder #6, and all the plugs were completely fouled. Car barely ran.

After I put the engine back in, and initial start-up and fine tuning to get it running 100% again, I was quickly shot down and staring at a cel, vsc, trac light on. Which after talking to the owner, I found out these lights came on 2 weeks prior to the removal of the engine.

Now i've been over the whole car, and after fixing a a/f sensor cel, misfire cel's, i'm still getting one code intermittently, everything has been checked, fuel pressure, timing (cam and ignition), I mean i've been over everthing at least 3 times. Even the nightmare of vacuum lines on this thing.

The code present now is:

PO171, system too lean (bank 1)
VSC light is ON
Trac OFF light is ON
ABS light, ON

The car revs freely and perfectly when in Park or Neutral, as soon as you put it in a forward gear or reverse, it bogs and loses power at 2k rpm. With the PO171 code coming and going. It's like the car is in Limp Mode, exactly how it acts.

Sorry it's so long, but i'm to the breaking point with this car and just want a satisfied customer to get his car back.

carguy07

Have the air fuel sensors been replaced since the motor was cleaned up? Does it run fine when the CEL is not on?

bob2200

You probably know this, but these 3 lights ON is the RX300 indication of CEL (check engine light). So you may just have one CEL code to solve.

singleslam

Bank 1, sensor 1 was throwing a code, it was changed with a brand new denso unit. Now the a/f sensor cel is gone. Now i'm fighting the po171 cel, system too lean (bank 1). But I did pull the #1 spark plug out and upon inspection could immediately tell that the system is in fact NOT too lean. There are no signs of detonation, and the plug did have signs of excess fuel.

As far as it running when the cel is not on, cold, hot, cel or no cel, the car acts exactly the same. As if it's in safe mode due to a sensor malfunction.

bob2200, i was aware of the lights being on due to a cel, but i'm not 100% sure that it's an issue with the engine alone. Is it possible for there to be a trouble code in the trans also?

I'm beginning to wonder if the bank 1 knock sensor has suffered some abuse or has failed, I should be able to verify with a timing light at the time of the misfiring, a failed knock sensor should pull timing out.

Sound right to anyone? Thanks for the replies, i'm desperately trying to repair this very, very misleading car and return it to the owner, who has been extremely patient

Russ White

Have you verified valve timing beyong the shadow of a doubt? Russ

sktn77a

iTrader: (2)

Well, the check engine lights usually put the car in "limp" mode until they can be cleared but this usually involves just locking out the O/D (and maybe the traction control). Have you re-set the codes?

singleslam

100% sure that the cam timing is correct. I've set this motor at #1 TDC so many times now that I could do it with my eyes closed.

Codes have been reset after every repair or tweak was made. Now i'm stuck with a single intermittent cel, PO171, system too lean (bank 1).

I'm going to take the upper and lower plenum off tomorrow and switch the knock sensors around and see if the cel switches banks. If so, than I know the sensor has failed.

Thanks again for the replies,
Matt

bufferdan

https://www.clublexus.com/forums/rx-...o171-code.html

singleslam

Thanks for the link, but i've been through that list more than once, and none of those are it.

On a side note, finally got fed up, dropped the car off at the dealer, they said initial inspection proved nothing, asked me if it was ok to keep the car a few days until they had a solid lead on what was going on, so let the fun begin.

Russ White

It's been a few weeks now....... What did the dealer find?

vinayan

cud also be leaking valves....did you grind valve properly...po.i71 is normally valve related

fastnoypi

Welcome. The OP hasn't posted since 2011. You can speculate he solved his problem and still driving with a big smile or his engine had a catastrophic failure. Lets hope it was solved

burteboy

Is there any misfie from # 1,3,or5 if so replace the vvt oil controller. iI think that is your problem. since the engine was sludged it could cause a malfunction on the vvt controller. Another check is your O2 sensor check thefunction. B1S2. one of those should correct your condition.

JAB

Burteboy: You are addressing your suggestions to someone who has not posted in 5 years . . .