I need help passing smog.

[JeepCherokeeGuy99]

this is making me think some of my bad gas mileage could bea bad cat on my Xj since every sensor on my junk is new and my last smog readings all passed but they were all very high (just below failing) which was starting to make me think that maybe my cat is going...

I would definitely think so. That or our state is just getting too ridiculous on our emission standards :dunno:

 

[blondejoncherokee]

yah im pretty good with the Xj maintence, every year I replace:
o2 sensor
cap/rotor
plugs/wires
air filter
test / adjust if needed/ replace if needed the TPS every 3 months or so
clean throttle body
adjust throttle valve cable
clean grounds

and last year replaced these maintenence parts:
Coolant temp Sensor, dizzy, cracked exhaust manifold and gaskets, battery, alternator, battery, grounds with 2 guage, coil , ps pump, crankshaft sensor,
installed ford 19lb injectors, fuel and air filter, IAC, vacuum harness, clean manifold temp sensor, 02 sensor,

this year already :
TPS, valve cover gasket ,

 

[Hoooper]

you replace the O2s every year? what? how many miles do you put on that thing per year?

 

[JeepCherokeeGuy99]

you replace the O2s every year? what? how many miles do you put on that thing per year?

That is pretty frequent. I do mine wvery 30,000 or 3 yr.

 

[Hoooper]

yeah, seems pretty excessive. Although thats one way to be sure they are still working good

 

[poomero]

ok I just put a new cat and muffler on and it still didnt pass. It did a lot better but not good enough still.

First readings.
HC
(15mph)MAX:123 mine 184
(25mph)MAX: 103 mine 173

CO
(15mph)MAX:0.73 mine 2.41
(25mph)MAX: 0.93 mine 2.24

NP
(15mph)MAX:711 mine 1174
(25mph)MAX: 613 mine 936

Second readings. (after new cat and muffler)
HC
(15mph)MAX:123 mine 139
(25mph)MAX: 103 mine 135

CO
(15mph)MAX:0.73 mine 0.88
(25mph)MAX: 0.93 mine 0.61

NP
(15mph)MAX:711 mine 0
(25mph)MAX: 613 mine 0

Tomorrow I am going to change the O2 sensor and hope that works.

Oh I forgot to put I changed the injectors to the 5.0 ones. I am thinking that they might be the issue because it is running to rich. Any thoughts on this????

Any help will be greatly appreciated..

 

[JeepCherokeeGuy99]

Definitely change the o2 sensors and you'll pass. Do you have a scan tool that gives a live reading? I have one in my jeep that displays real time data while your driving, it will tell you if your running rich or lean as well

 

[poomero]

No I don't have one. I don't have any tools like that. All I have is a regular set of tools.

 

[JeepCherokeeGuy99]

Make sure you change both the upstream and downstream sensors. Especially since they are only $25 a piece for a universal one.

 

[Hoooper]

make sure you drive a bit on the cat before you smog after getting it replaced. Ive seen info about new cats that seems to show they actually dont start to work best until they are heat cycled a few times

 

[JeepCherokeeGuy99]

make sure you drive a bit on the cat before you smog after getting it replaced. Ive seen info about new cats that seems to show they actually dont start to work best until they are heat cycled a few times

X2 :thumbup:

 

[poomero]

Ok I will take it out this weekend after I change the o2. Thanks for the help on this guys. I will keep you all posted with what the outcome is.

 

[JeepCherokeeGuy99]

Ok I will take it out this weekend after I change the o2. Thanks for the help on this guys. I will keep you all posted with what the outcome is.

Also it is worth erasing the old ECU or PCM memory.​

• Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
  Reconnect the Battery Cable
  Turn Ignition Switch to the “On” position but DO NOT start the engine
  Turn Headlight “On”
  Turn Headlights “Off”
  Turn Ignition Key “Off”

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory. When you get the engine up to operating temperature, the PCM will start to collect data for the “Adaptive Memory”. The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.


Since you upgraded the injectors and probably didn't do this, it would be a good idea to do so as soon as you can.

 

[poomero]

WOW ok I will do that tomorrow after the o2 swap.

 

[vagabond]

Its a Renix if its a 90, and those as far as I know don't store codes. I'm sure i'll be dealing with some of this stuff when I smog my '89 later this year, as I barely passed smog last time.
There was a thread in oem somewhere about testing the renix 02 sensor and testing the heater in it.
Other than that I have nothing useful to contribute!

 

[poomero]

It is a RENIX your correct.

 

[JeepCherokeeGuy99]

Its a Renix if its a 90, and those as far as I know don't store codes. I'm sure i'll be dealing with some of this stuff when I smog my '89 later this year, as I barely passed smog last time.
There was a thread in oem somewhere about testing the renix 02 sensor and testing the heater in it.
Other than that I have nothing useful to contribute!

Doesn't matter if it a Renix or not. Your vehicle still has a computer that runs off of pre programmed settings. When you reset it. The computer will find the best air/fuel ratio for his application during the next 50 warm ups. His car is currently running on factory presets.

 

[vagabond]

Doesn't matter if it a Renix or not. Your vehicle still has a computer that runs off of pre programmed settings. When you reset it. The computer will find the best air/fuel ratio for his application during the next 50 warm ups. His car is currently running on factory presets.

While digging through the renix FI manual, its not clear if there is a manual reset mechanism built into the system or not (aside from correcting the problem with the system and 15 faultless start cycles)...

So far what i've gathered is that as soon as the ecu in the renix system senses a fault or the A/F ratio gets screwed up, it dumps to open loop mode or some such nonsense.
So far all the language present in the renix FI manual makes me think it adjusts the FI ratio on the fly based upon pre-programed modes of operation and does not store sensor input, but rather stores fault codes, which are accessed by the infamous drb2 tester which I hear is hanging out with a unicorn.

Of course this is starting to make me wonder a few things...

A: What the hell was I saying before.

B: I wonder what could be learned from pins 1&2 on connector D2. (rs232? voodoo? pixie dust? )

c: What other easier ways to diagnose common problems could be found through the two renix diagnostic connectors.

 

[poomero]

well that went way over my head but thanks for the info.

 

[poomero]

I just got done changing the 02 and the oil. I am going to take it in on monday and see if it will pass this time. I will let you guys know.