rigoi

Need help please.

here are my readings
15mph co2 14.9 o2 0.1 HC max 61 meas 107 CO max 0.51 meas 0.26 NO max 490 meas1137

25mph co2 15.3 o2 0.0 HC max 36 meas 53 CO max 0.49 meas 0.05 NO max 730 meas 316

Anyone please help!!!!!!!!!!!!!!

MAD_MIKE

Toyota 4-5 gas pdf

This is a great PDF for anyone who has to smog. Read it, Learn it, Love it.

MAD_MIKE

When was the last time the car had a full on tuneup?
Plugs, wires, O2(not beer can bosch type) yadda yadda?

rigoi

Before I tested the car I change the plugs and change the oil. Today I bought new wires, dist.cap and new rotor. I have never chaged the O2 sensor.

holmesnmanny

That link Mike posted looks great. I will add that normally high NOX and high HC is a result of an EGR valve and EGR passages that need to be cleaned out.

jdmcertified909

ive seen this on several cars too. and the owners go doing tunes up o2 etc. when ive found it was a stuck open thermostat failing them and giving them high hc & no.

rigoi

I clean out the passages yesterday and they look good. Change the thermostat before doing the smog check. How could I check to see if it's stuck?

jdmcertified909

IF ITS NEW I DONT THINK IT WOULD OF FAILED. ONLY WAY IS TO TAKE IT BACK OUT AND WARM IT UP A COUPLE OF TIMES IN IN A POT AND SEE IF IT EVER GETS STUCK OPEN

DCFIVER

A stuck open thermostat will not increase NOx or HC

wolfy47

Is the car misfiring?? If I remember running lean can cause both high HC and high NOx

DCFIVER

Looks like a bad cat.

holmesnmanny

yeah, I would replace the cat now.

jdmcertified909

yes it does a cold non normal operating temperature car will burn more gas thats what the ect is for. it reads the coolant temp and send data to the ecu for rich or lean conditions. not only have i seen this on hondas but specially on muscle. like a camaro i worked on. it wasnt passing smog and i seen that the stat was open all the time not allowing motor to get hot enough i told him to change the stat he didnt believe me that it was that. so he took it payed $500 for each cat this camaro had two cats plus labor total he said he paid $1700. and it still didnt pass. and the cats were original. it had the same high hc & no the new cats didnt help at ALL. so HE bought the thermostat changed it him self and took it back in and it passed right away

jdmcertified909

and would you also plz explain why your calling me a liar? when its from my own experience? from what i have seen. from what i have actually fixed. and seen them pass after the new t stat was put in?

wolfy47

cats really dont go bad by themselves...they usually go bad because something makes them go bad...so it would be best to fix what made it go bad in the first place

holmesnmanny

he's got an old car, dude. Cats do eventually wear out.

DCFIVER

Still wrong...
I did not call you a liar. I said you were wrong. You have minimal to no understanding of exhaust gas analysis and you simply connected the dots during an event you did not comprehend. Many "mechanics" do it all the time.You are wrong. Period.


The exhaust gas readings that the OP put up speak for themselves. It quite obviously needs a cat. But you do not understand what you are reading and are incapable of making the proper interpretation, same way you think a stuck open thermostat will raise NOx...
The noble metals in cats do actually degrade as a natural progression. Particularly in substandard after market cats.

rigoi

One of the wires on the temp. sensor on the upper radiator hose had broken off. Could that of cause the car to run lean?

jdmcertified909

so your saying that the camaro after a FULL tune up and two brand spanking new cat and still not passing is just me? but after the thermostat change it passed thats still just me? so when an engine is cold it doesnt throw more gas becuz its telling the ecu its cold so its running rich? and gas getting passed thru cats and unburnt fuel? so thats not the reaon of high hc & no? mmmmmmmmmm interesting. wish i still had that print out he gave me after the brand new cats were installed. the numbers of high hc & no decreased by a hair. but when the thermostat was changed it passed. with flying colors. unburnt fuel is hc but ok. i believe proof more then i believe people especially if i seen it with my own eyes.... but w/e not going to argue with you.

jdmcertified909

the one thats on the housing right?? if correct thats your ect sensor *engine coolant temp sensor* thats what tells your computer what temp the coolant is. and it either makes it rich or lean. but i cant remember which it is if its not completing a circuit. i would say yes im not in shop right now to look it up im at home. but i believe that yes a non complete circuit would be lean condition.

holmesnmanny

I believe when the car is cold it runs rich. That's why you get excessive HC when the thermostat is stuck in open position.

holmesnmanny

That switch only controls the fans when it's really hot and the car is turned off.