kobayashi

For the past 3 months I have been wrestling with the PO133 code, or Bank 1 O2 sensor slow response code on the 2000 TL with 117k.

-I first swapped both front and rear O2 sensors with OEM replacements which delayed the code for about 6 weeks but it came back.

-I swapped air filter and plugs and reset the code and it came back almost immediately.

-Then I spoke with 2 different Acura techs on seperate occasions. One suggested a blocked primary cat which I didnt explore and the other suggested a blocked EGR system which I did explore and cleaned the system with some help from these forums . Cleaning the EGR system delayed the MIL for a while longer, but back it came.

Any thoughts on this problem? Anyone else had it? Might it be a blocked primary cat? This didnt make sense but who knows.

k.

fsttyms1

did you take out the egr itself and look for any obstruction in the lower manifold where it bolts up?

kobayashi

What is the "EGR itself"? You mean an EGR valve? I was under the impression the Acura didnt have one.

I took off the top EGR plate in my first exploratory pass and cleaned it. Then I came here and saw I should take off what I think is termed the large upper manifold and cleaned it. But I dont think I made it to a lower manifold and no I dont think I saw anything that looked like a EGR valve bolted to anything. All I found was a series of passages through the manifold and what appeared to be a metering gasket below the EGR plate.

I did think the cleaning the EGR helped because it did delay the code reappearance about 4 days. Maybe something is still blocked I havent gotten to.

TIA for any additional help. Pics would be great.

k.

fsttyms1

Think about what you just said. of course whe have a egr. if we didnt we wouldnt have clogged egr ports and you wouldnt have removed the top egr passage plate

the "rusty" part is the egr

kobayashi

Well as I understand it, EGR stand for "Exhaust gas recirculation" which is an act not an actual device. We definitely have an EGR system, you can have an EGR valve, but the way you used EGR naked threw me. I was thinking there was some specific component you were referring to, which I see you were.

Thanks for all the help though. You cleared it up. I havent touched that part - yet.

k.

kobayashi

My Helm's manual seems to suggest what you have circled is the Evaporative Emission Canister Purge Valve. Part of the EVAP not EGR system.

The frustrating bit, now that I'm searching it, is the Helm's manual alludes to an EGR valve but doesnt identify it unless I am missing it.

k.

kobayashi

Fstty the parts guy says you are correct that this is the EGR valve. I dont know what to make of the manual entry. Maybe I have a new doorstop.

So I pulled off this EGR valve and the interior seems relatively spotless. Which begs the question - why? Why is downstream of this area so fouled with carbon deposits but this upstream unit is relatively spotless? The EGR valve says "Assembled in Mexico" on top, maybe its been replaced already? The car had 70k on it when we bought it.

k.

fsttyms1

exhaust comes into that.the computer (depending on what sensors tell it to do) opens and the exhaust gasses go UP into the intake manifold. that is typically (like my DIY) on the upper manifold gets clogged. those small ports and tracks are just to small and allow buildup..

if the egr and the main port leading to the IM are open, id start to look into other areas. possibly a bad cat or bad wire somewhere???

Pure Adrenaline

iTrader: (2)

Agreed with fsttyms1. Kris knows what he's talking about, so follow his suggestion and try it out.

I've been plagued with P0135 which is for the heater circuit malfunction. I'm on my 4th primary sensor now.

kobayashi

Even the relatively good sized port coming into the upper manifold had some pretty heavy deposits. The EGR valve by comparison looked like it had coat of rust colored dust. No oily gummy stuff.

The wires are good. The idea about a blocked primary cat may have some merit. I dont know why that would affect the O2 sensor in front of it though, unless a blocked cat builds heat or pressure and causes the O2 sensor to read poorly.

k.

fsttyms1

a blocked or bad flowing cat will produce alot of heat which may be damaging the o2 sensors. unfortunatly there is no easy way to inspect the cat with out taking it out

Lawaia

A bad or malfunctioning O2 sensor will usually cause a rich condition which in turn provides too much unburned fuel in the exhaust system. When the unburned fumes come into contact with the heated catalyst in the converter it will ignite causing the converter to overheat and melt.
Check your converter by banging it with a rubber mallet to see if you hear metallic rattles (sorta like a bunch of ball bearings in a coffee can). This sound would indicate the ceramic and catalyst falling apart.

kobayashi

I'll check the cat out next. The tech said some shops could flow test the cat, I guess by removing it.

k.

kobayashi

Just an update. The deep cleaning of the egr maze/intake manifold and egr valve held off the PO133 code from my last post til now. It popped up yesterday again. Going after the cat now.

BTW I ended up removing the TB from the upper intake to make cleaning the upper intake easier. When I reinstalled the new TB gasket I coated one side with a thin coat of antiseize compound hoping that cracking it again wouldnt shred the gasket.

k.

kobayashi

Further update:

Tomorrow I am gonna try the anti-fouler mod and see what happens. Apparently on some older Acuras a repetitive PO133 was solved by a revised O2 sensor design with fewer holes in the tip and the anti-fouler mod simulates this.

k.

Pure Adrenaline

iTrader: (2)

Keep us updated, kobayashi! Good luck.

kobayashi

Just realized I never updated this thread with the solution to this problem. After 3 new o2 sensors and various other attempts we finally took it to another Acura dealer with an apparent wizard of a mechanic that figured out the problem. The new timing belt(installed by a non-dealer) had been installed one tooth off. No problems with that trouble code since the fix.

k.

fsttyms1

Wow.. Good thing they found that. Too bad it wasnt sooner.