z06ufgrad2002

My experience with this same problem is this:
First time I got the codes I changed both O2s and code went away for ~6 months. Then it came back. O2s are swritching normally. Changed the O2s again and code is gone again. Car also has OE injectors.

I will be turning these codes off if they come back again.

Wades SnS

iTrader: (2)

I myself have this same problem and would like to know if there is a way to calibrate the O2's to fix it? It seems as if the addition of a cam with lap allows for raw fuel to be pressed into the header. cooling things, Also exhaust without a big cam that is also run through a LT where there is less pressure than a manifold, due to more volume, allowing for a cooler condition. Also LT's have O2 placement further away from the head than a manifold again ...cooler condition. So lets say now you rev your engine to 2000rpm's. Does the oscilation increase? Mine does but it still seems as if less pressure and O2 placement would have some affect on the calibration, only now the exhaust is moving faster so it is closer to what the computer needs to function properly. These are all ideas that I have had for some time but I don't have the tuner knowlege to test or attempt to fix(calibrate O2's) so if someone wants to test it that would be great. If I am way off that is fine too but I would like an explination as to why because this seems to make good sense to me.

ZL1Killa

iTrader: (17)

you will not be told you run into OL... might as well get it tuned OL if you are going to cut the codes off.

each case of these codes I have noticed is very picky(well i guess every code is)
but its got to be something you can change for it, every issue can't be headers

Billiumss

iTrader: (11)

Would adding more timing help create more heat around the low RPM and low load cells? Or maybe add 25-50 more idle RPMs?

z06ufgrad2002

No need to run OL if the P0133 and P0153 codes are turned off. As there are ~4-5 different O2 sensor codes that will still fire if a failure condition is reached.

ZL1Killa

iTrader: (17)

not P0133 or P0153 but the car will go into OL if P1133 and 1153 codes are triggered, of course once you restart the car it will be on closed loop but only for a short while

SideStep

That was me.... here is the post:

I no longer have the Oxygen Sensor Circuit Slow Response error codes...


I am embarrassed to say I did not follow the "change one thing and see how it reacts" normal scientific process... I changed two things just on a lark to see what would happen. I have been running fine for a month now with no error codes. I use to get several each time I drove the car.

Here is what I changed...

***I reduced the Closed Loop Proportional Base vs. Airflow Mode by 15%

and

***I reduced the Minimum Injector Pulsewidth by 10%

I have noticed, when scanning, my switching pattern is more active, though the highs and lows are not as high or low as they were before these changes.

This is just an FYI for anyone chasing this problem….

Billiumss

iTrader: (11)

SideStep,

Thanks for posting this info, this should help a lot of people out! Did someone share this info with you or did you just figure it out on your own? Just trying to learn a bit...

Bill

SideStep

Hey Bil,

I tried this after reading a post here that hinted but did not define this as a possible answer. It was just a shot in the dark that I tried them at the same time (not the right way to implement changes). It would be easy to back them out and see if one of the steps was all I needed, but after months of P0133 and P0153 error codes I don't want to go back...

I would like to point out that the values I used (15% and 10%) were just guesses. Also, I have noticed, when scanning, my switching pattern is more active (obviously), though the highs and lows (of the wave) are not as high or low as they were before these changes, just more ups and downs.

Billiumss

iTrader: (11)

Thanks for your insight!!!

ShevrolayZ28

iTrader: (4)

Has anyone else tried this?

jimmyblue

iTrader: (11)

I would like to see someone do it incrementally and capture
idle O2 waveforms at stock, -20% and -40% (or something
like that) on the proportional fuel table at same conditions
(warmed up identically etc.). Someone who has the problem
showing up already, as raggedy O2 waveforms.

98form

iTrader: (5)

I am currently having getting the insufficient switching after LT header install and was wondering if anyone has had any success with these changes. Very interesting info here.

I also read that switching the Pre-Cat Camaro sensors to the Vette Rear/Post-Cat O2 sensors can do the trick since they supposedly have more heater power so the sensors can "stay lit" despite the cooler temperatures.

Could these problems also be attributed to leaks within the exhaust system, which would cause the overall exhaust to be cooler from letting the heat escape or cool air in?

senicalj4579

iTrader: (41)

b u m p

94camaroz28lt1

iTrader: (1)

I have swapped a 4.8L V8 into a 04 Colorado with long tube headers and high flow cats, large diameter 2.5"dual tail pipes, I have had a slew of codes the most annoying being P0134, and P0154 insufficient, switching codes??? Is this from my 1 3/4"long tube headers?? I have Hp tuners can I tune the heater circuits to stay on longer, and or the check for this code to hold off longer or only above 2000 rpm??




I fund out that the bank 2 sensing wire was to small a gauge going into the PCM changed it to a larger one, and my PO174 bank 2 lean and PO300 , went away, now I just have the P0134 , and P0154 insufficient o2 switching codes when I let it idle for about 3 minutes, and it cools down. Do you know if the o2 sensor circuits should stay on all the time, or are they controlled by the computer, if they are controlled I need to some how get them to stay on longer, or I need to wrap the exhaust and o2 senor to keep the heat in!!

Vacuum readings;
-warm idle 20 hg
- quick rev drops to 7-8 hg, than back down to 20 hg
- reving at 2000 rpm 22 hg snap throttle shut drops to 18 hg, than back up to 20 hg
- double tap rev around 4500 rpm 26 hg than back down to 18-19 hg and idle at 20 hg

These seem fairly normal to me??

How can I test the O2 heater circuits, and or make them stay on longer, or come on always on idle after around 2-3 minutes??

muncie21

iTrader: (14)

O2 switching is the time from peak to valley on the O2 sine wave. If your O2s never switch (flatline) then insufficient heat-up could be a potential contributor. However if your O2s are lazy (slow switching) I doubt that making them hotter will help. You'll need to play with the O2 threshold tables in that case, or potential tweak your injector table (if the laziness is only at idle). The short answer is, don't worry about it, if they are only being lazy, it doesn't really hurt anything and is only an annoyance.

flamedragoon

This information is great because my car is throwing these codes as well. The biggest differences are I don't have long tubes and I have my oem injectors. My car is a 2000 z28 automatic ls1 with 85,000 miles. Only mods are an slp intake box. And while its throwing these codes the car bogs down horribly Driving home the other day it on the highway I was going about 75 when it started bogging down and wouldn't go above 35. I was pissed. I had a scan tool and pulled pre o2's had insuffient switching. Last season I replaced the pre cat o2s before storing the car for the winter but the problem was still there. Car will just seem lazy and not accelerate at all at times. So my question is how do I adjust my fuel trim levels or where can I get them adjusted? Or does this sound completely like something different and should I move to another thread. Either way it's extremely frustrating and any help is greatly appriciated!!

94camaroz28lt1

iTrader: (1)

Only having a aftermarket intake is not going to effect fuel trims.

I think one or two of your stock 02 sensors had enough, and now perhaps your cats are cooked and therefore your exhuast is now plugged, and that why it won't go passes 35 mph?? What are the codes your are getting? are the for the front or rear 02 sensors, and how long has the check engine light been on for?? Do not change your fuel trims!! Fix the mechancial problems first, than get it tuned if you want!

flamedragoon

No I definitely agree. I'd rather fix it mechanically then have to go through the hassle of getting it tuned. The codes I'm getting are p1133 and p1153. both for the pre cat o2's. And it's weird because it doesn't bog down like that all the time. That was just the worst it has happened. And I was thinking about replacing the cats but I don't want to do that till I figure out what the underlying problem that caused the cats to fail if thats what happened. Thank you for your help.

94camaroz28lt1

iTrader: (1)

are you 100 perecent sure you have no exhaust or intake leaks??

with the car cold spray down the entire header, and cylender head with brake clean. let it dry than fire the car up and let it run for 15 minutes are there any black stains of soot under the manifold ports, this indicates and exhaust leak from the header to the cylender head.

also wiht the car idling for about 15- 20 mintues and soft rev hear and there over light colored concrette or cardboard should show little puddles of water with weired black bubbles in them, this indicates an exhaust leak directly above the puddle, look for soot stains on the exhaust connections and the chassis of the car.


to check for intake leaks pull the a/c relay to stop the engine from surging as the a/c kicks in and out, also pull the fan relays or unplug the fans so they don't cut you and so it is easier to hear! You can even remve the drive belt, to further cut down on niose. Just make sure the car is cold, or warm, not hot, and don;t let it over heat, only run it this way for 1-2 minutes. Listen for air leaks, and spray cab cleaner on all the pvc, vacuum hoses intake seals, throttle body seals, and inlet air tube conections after the MAF sensor, oe at a time, and change in enigne sound indicates a vacuum leak there.


also won't hurt to clean the Maf sensor wiht electrical contact cleaner, make sure the cleaner is 100 % evaporated befoe plugging it back in. Never use oiled air filters on these engines clogs up the MAF sensor, cause it to run rich, foul plugs, O2 sensors, and cats!!

Any chance someone ran leaded gas?? that would kill the o2 sensors in hurry!

When was the last time plugs wires were done?? Start wiht basics first than work your way up the top. BTW O2 sensors are considered regualr mantanice, and should be changed every 40,000-50,000 miles for best economy.

what puzzels me is that both O2 sensors went at the sme time! what are the chances!! check that the wires arn't burnt, and that the are clean, the O2 sensors require outside aire from the wires and connector O2 sensor side, this is the reason why you neve slpice wires on the o2 sensor side.. vehicle side only!