Cascade Crew

91RSVert

ok, back in jan or so, I made a post having problems with o2 sensors...

http://cascadecrew.org/phpBB2/viewtopic.php?t=6620&highlight=

so, now that we finally have some decent weather, fixed an exhaust leak. I am doing tunes.

I swapped sensors left for right as suggested in the post due to the cost. The same side is still removing fuel... listed as bank 2. But I am not sure my sensors are on the correct side. I will check that in the next few days (hopefully)

So I am not feeling a missfire. But what else would cause 1 side to be about 10% different then the other side?

IROCDave · Posted: Mon Mar 01, 2010 7:14 pm Post subject:

Maybe I missed something in your earlier thread. You have an 02 sensor on each header?

You mentioned spilling coolant on your sensor, from what I have read about anifreeze and 02 sensors, they are not compatible. Antifreeze ruins 02 sensors.

I bought a heated 02 sensor from Lingenfelter 10 years ago and if my memory is correct it was around 60 bucks. I replaced it several years later with a single wire, didnt make a difference. Did they go up in price?

91RSVert · Posted: Tue Mar 02, 2010 5:09 am Post subject:

Yes, I have a sensor in each header.

As asked before, I thought It would damage them as well. But I swapped sensors left to right(as suggested), and I'm getting the same reading(s).

I run sensors for an 2002 express van c2500 with 350.

Dewey316 · Posted: Tue Mar 02, 2010 5:19 am Post subject:

if both sensors read the same, and you have one bank that isn't reading right, then you have something that isn't right. Start looking at a mechanical issue on that bank.

aaron_sK · Posted: Tue Mar 02, 2010 7:09 am Post subject:

In my experience, sensors that are failing start to dump fuel, not pull it.

I'd start looking for a vacuum leak. You might also consider swapping the injectors from bank to bank to see if that changes anything.

91RSVert · Posted: Tue Mar 02, 2010 7:59 am Post subject:

dewey, correct. But where to start?

aaron. Correct, it is dumping fuel and the pcm is having to remove about 10% on the one side. Injectors are BRAND NEW (no reman, no cleaned). Have onboard vac gauge, It is the steadiest it has ever been on this car.

Twilightoptics · Posted: Tue Mar 02, 2010 10:05 am Post subject:

Internal vacuum leak. Like intake gasket sealing. PCV on that side? PCV would take up air/fuel space and possibly disturb the mixture.

Doesn't really sound all that "off."

Possible valves not sealing. All it takes is one cylinder to cause a reading to be off.

10% afr? IE one side reads 14.7 the other reads 13.23?

Front mounted TB plenums can be up to a full point off from the cylinder in the front, to the cylinder in the rear, that's normal.

If it runs good, your lash is good, it's not PCV related, and your valves and rings are sealing...... run it.

aaron_sK · Posted: Tue Mar 02, 2010 10:29 am Post subject:

Do the plug readings back up what the O2 is telling the ECM (i.e. richer side has darker plugs)?

91RSVert · Posted: Tue Mar 02, 2010 10:34 am Post subject:

tw...

It was even for a while after putting the engine together, then it went off. Maybe it sealed initally, then went bad? Dunno.

As for % numbers, it has nothing to do with AFR. I'm talking when trying to do a data log (using efi live) you read your o2 sensor readings to obtain your ve table, whatever its off by, is what you need to change in your VE table(table is just like obd1). So bank1 may be reading -3.x%, bank2 would be -13.x%. At idle its within 1.5% which I'm told is fine n normal. But under load is when its off and told that much is unacceptible/wrong. 3-4% from side to side is the max off, or something is wrong.

So internal vac leak
cracked plugs?
plug wire bad/not on all the way
injector got plugged after install?

:edit: aaron, you posted while I was typing. I havent checked them as I dont think I have drove it enough to do that.

91RSVert · Posted: Mon Mar 08, 2010 12:48 pm Post subject:

ok, this weekend I traced out which sensor was which bank.

I am having problems with the right side. Which I have found I didnt tiewrap my back 2 wires, and looks like one of them got hot on the header.

Will have to wait tell friday to get a new set of wires. But hopefully this is it.

amazing what you look over when you think you have it all done, but keeps leaking Bashy Bashy

aaron_sK · Posted: Mon Mar 08, 2010 5:34 pm Post subject:

Right side = passenger side?

You don't want to ziptie the back two wires on the driver's side. At least not to each other.

91RSVert · Posted: Tue Mar 09, 2010 8:09 am Post subject:

Yes, right/passanger.

My setup is soooo far from stock. All wires are tied together in 2's to keep them away from the headers.

91RSVert · Posted: Tue Mar 23, 2010 4:15 am Post subject:

replaced the 2 damaged wires, fixed about 2%

Found out I had some loose power wires. Fixed.

Still off by about 7-8%

replaced distrib cap, fixored (atleast on drive in, will see about drive home).

WOOT!! Keep fingers crossed