Algrus

I recently purchased an LS 400 from a family member for a great price. Unfortunately, it won't pass smog and it is not the fuel control system because the A/F ratio was nearly perfect. It runs great except for some squeaky brakes. Any suggestions as to what are common problems?? Advice? Thanks!

LScowboyLS

please dump the diagnostic codes using the procedure here and post them back to this thread so we can see what's up

common remedies to pass smog:

replace plugs, wires, distributor caps, rotors
find and fix vacuum leaks and intake tube leaks (post-AFM)
get leaking ECU capacitors replaced
replace engine coolant temp sensor (behind passenger side coil)
replace O2 sensors
replace PCV valve
replace air filter

please only use original factory Toyata parts for the above, except O2 sensors and wires and plugs, where Denso or NGK are fine. on air filter and PCV, FRAM or any major brand

Yamae

The EGR pipe is also one of those items to be checked especially when the NOx is more than the limit.

sha4000

iTrader: (1)

+1 on the EGR I have not heard anyone complaining about that in a while.

RA40

iTrader: (6)

Welcome to Club Lexus.

What portion of the smog did the car fail? Post the measured readings.

Algrus

I couldn't find the spark plugs to replace them. I'm having problems understanding the directions on how to dump the diagnostic codes. I'll look into that more. Thanks for the quick response.

LScowboyLS

the NGK or Denso spark plugs for the LS400 are super easy to find at many places online, or at any local auto parts store, do you need the NGK or Denso part numbers?

as far as the diagnostic codes, just follow the procedure I linked to, and insert a little piece of wire or even a paper clip into the diagnostic connector in the correct holes as per the instructions and count the blinking lights!

Algrus

Oh wow!! I didn't know a paper clip would work. I'll end up doing that later this week. I literally couldn't find where the plugs were and I was looking under the hood for awhile!! It was not anywhere in the manual either.

Algrus

Emission Test Results

Category... CO2 O2 .. | .. HC (PPM) | CO (%) .......| NO (PPM)
Test RPM MEAS MEAS MAX GP MEAS MAX GP MEAS MAX GP MEAS
15mph 1384 14.10 0.78 56 265 272 0.46 1.96 0.49 477 1890 904
25mph 1386 14.22 0.64 32 215 240 0.43 1.93 0.36 481 1690 736


4-gas measurement lambda=1.004 and A/F ratio=14.75
5-gas measurement lambda=1.004 and A/F ratio=14.76

LScowboyLS

the spark plugs are under the hood, and so is the diagnostic connector! (where you use the paper clip or jumper wire)

LScowboyLS

from your results, it looks like you are failing on almost all tests, you definitely need a full tune up, plus EGR attention, plus hunt for vacuum leaks.

it's likely that this car has been ignored on maintenance for some time, and pretty much everything listed in post #2 would be a great idea

how many miles on this beast?

Algrus

230,000! I picked the car up for 750 so it was a steal but it hasn't passed smog. I'll post the results for the diagnostic code test at the end of the week. Where should I go for a tuneup? Does it have to be a Lexus center?? How much would I be expecting to pay? Thanks for the help!

LScowboyLS

I would order all of the parts from an online Lexus dealership (such as Sewell Lexus) at a discount, and have the most respected independent mechanic in town do it - one who has worked on a lot of Lexuses

you register with Sewell to get the Club Lexus discount

the plugs and wires and PCV valve and air filter come from amazon or rockauto.com, probably ~$350 for all of the parts

Algrus

Is this the EGR pipe?

2560150010
EGR PIPE SUB-ASSEMBLY NO.1

http://lexus.sewellparts.com/oem-cat...S400-1993.html

sha4000

iTrader: (1)

Yes that's the pipe. Check to see if it's cracked.