my car is 1991 CRX EE8 VTEC EDM , it has 2 lambda sensors
can i clean a o2 sensor ?

if yes, with what ?

 

Various spray cleaners, like MAF cleaner, carb and choke cleaner.... I have never seen this fix anything though. Why do you feel like you need to clean them?

 

You can clean them.
If the holes in the metal are visually clogged then it might help.
Otherwise, cleaning is just going to make them clean and will not repair them to working condition.

 

i have this problem, on my honda crx b16a1 edm 1991

my engine on idle and if i press on the gas fluctuates 200/300 RPM

COLD don't fluctuates
hot engine fluctuates 30 seconds after starts running ( the first 30s when is hot don't fluctuates )

I've done:

-IACV-
clean 2 times, i close the IACV and engine still fluctuates

-FITV-
clean 2 times, i close the FITV and engine still fluctuates

-vacuum system-
the vacuum system was verified with proper gun, and check the tubes, tube are like new
check with proper smoke equipment (smoke will emerge on leaks)
test it with carburettor cleaner

-PCV valvule-
replace for a new one from HONDA

-TPS-
tested 3 - all tuned to 0.45v open , 4.55V closed

-TB-
clean and tested 2

-IAT-
temperature sensor admission was clean

-Bleeding Air In Cooling System-
done several times

-ECU-
tested 2 stock ECUs

-injectors-
4 hours ultrasonic cleaning

-LAMBDA
installed new two o2 sensors DENSO DOX-0125

-valve lash
in 0.15mm
ex 0.20mm

-ignition timing
15 deg.

-engine timing
its ok ( set properly )

-cams are proper alignment

-compression check
cylinder 4 - 11.5
cylinder 3 - 12.5
cylinder 2 - 11.5
cylinder 1 - 12.5

-spark plug wires-
3 sets tested (2 used, 1 new NGK)

-spark plug-
tested 2 sets (NGK BKR6E-11 - 5304 Denso Iridium IK20)

TESTS with STRANGE results

if i unplug the TPS, engine dont fluctuates
if i unplug a spak cable (any one) and plug again engine stop fluctuating
if i unplug the TWO o2 sensors or remove it on REPRO engine dont fluctuates


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i made other approach...

i decide to disable the first oxygen sensor on the ECU ( on BRE )

idle problem solve, with 1st o2 sensor DISABLE and 2nd O2 ENABLE

(i think thats why the idle start after 30s, because is when ECU starts making adjusts on AFR)

do i have the 1st o2 sensor defective ?
my ECU gives me NO errors

is normal to have a defective sensor with no ECU error ?
could be a exhaust manifold leak ? a leak on 1st o2 sensor hole ?

just cleaning solves the problem ?

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Honestly, I dont know for sure. But you have covered all the simple/basic things I would have checked first, it could be a 02 sensor.

 

i hope is the o2, dont know what more can i do

 

found out that the second o2 sensor had the wire cut

replace the second o2 sensor (for a used one), and didnt solve my problem

 

Hi there

We must talk in crxpt but.. anyway

Have you ever tried to change o2 sensor n2 to n1 position. If you do this and you disable the other one you will sure that one of the o2 sensor is damaged!

If you solve the problem please post it, because i'm already with lambda problemas too..

regards

 

Hold on, so the rear o2 had a wire cut? And when you put in a known working one with the wire(s) intact it did what?

 

i had the N2 o2 sensor wire cut,
so i replaced the N2 for other o2 sensor
with the N1 and N2 o2 sensors ON, engine stills fluctuates

on BRE i disable only sensor N1.

with N2 sensor enable and N1 sensor disable (on REPRO) my engine dont fluctuates ...

time to replace N1 sensor ...

 

-LAMBDA
installed new two o2 sensors DENSO DOX-0125

didnt solve my fluctuation problem

what more can i do ????