so you think you're getting un-metered air coming in via a bad rubber snorkle hose, which would be read by the upstream o2 sensor as lean and force a richer mixture? i think i'd replace the snorkle hose or where ever the air leak is. do a cigar smoke test (google on youtube for specifics) to find out which hose(s) is/are 20+ years old and not holding vacuum/air as they should.
tony

 

Ha. I had not thought of the downstream sensor. Before you mentioned this, I was thinking:

1. The A/F ratio is kept to spec by the ECU
2. Extra air comes in from the leak and ends up being lean in reality

But of course, the logical conclusion is that the ECU notices this and squirts more fuel in to make up for it.

Doh, should have thought of that!

Are there some readings over OBDII that I can monitor to confirm?

Hmm, smoke test.

What is a good place to get good quality hoses from?

How much do they cost new (vacuum hoses on this model)

 

yep, just set up graphs for your o2 sensors to monitor short term fuel trims. the haynes will tell you how yours should react but normally, they'll swing above and below the line from ~ .1 to .9
if you get higher than .5 (up to .9) for a majority of time, then you're rich. lower than .5 is lean.
i don't know about hose prices or places to buy. i've been lucky enough to snip off the old ends and keep the old hoses so far.
tony

 

Your car will run rich upon COLD startup - that is perfectly normal. This is because the car is cold, and because the 02 sensor needs to heat up before it can start reading. Cold engine needs more fuel to run - air density, so on and so forth.

Once your car is warmed up, the computer will lean out the mixture and will eventually go into closed loop fuel control once the O2 sensor warms up and starts functioning.

Back in the old days, some cars had manual choke that you would pull during warm up or the car would die. Then there were the cold start injectors that would spray extra fuel during warmup. 4th gen Camry brains were sophisticated enough where the computer could richen the mixture enough without the extra injector.

This is also why some new cars have electric block heaters and heated O2 sensors - the faster you can wam up the car and components to operating temps, the faster it will "stop polluting".

Again, perfectly normal for these cars.

EDIT: The smell of gas upon cold startup is not only because of fuel enrichment, but also because your catalyst only starts working when it reaches working temps. So when everything is cold, your car is essentially cat-less and smells like one. Once it warms up, cat starts burning unburnt fuel and your exhaust no longer smells like gas. Again, totally normal.

 

You should not be smelling raw fuel at start-up, even for cold start rich. I'd check for fuel leaks to be safe.

Even though you have a broken inlet tube the ECU will compensate to a point and add extra fuel that the O2s tell it it needs.

Are you experiencing any idle problems?

 

Are you experiencing any idle problems?

Uh, 1k - 1.2k RPM (high?) idle on start up.

Once the car has been running for a while, the idle is more like 800 RPM

What are we looking for here or thinking about? :|

 

1k-1.2k idle RPM on a cold start is perfectly normal. Warmed up it should be 750 +/-50 RPM, so you're good there.

As others have said, the ECU will ignore the O2 sensors on a cold start until they reach operating temperature; called "open loop" mode. That's why heaters were added to O2 sensors, to reduce the amount of time the ECU runs in open loop mode using default fueling curves. Your '98 has heated O2's. It should go into closed loop mode in less than a minute.

I'd look for a fuel leak. If it was running poorly, I'd suspect a stuck-open injector, but that doesn't sound like the case with yours.

 

What are we looking for here or thinking about?

Rough/loping idle. OBD systems are designed to adjust to variance from perfect stoichiometric ratio. I think if you're smelling raw fuel you'd get a code.

 

I think if you're smelling raw fuel you'd get a code.

No code, but as the guy who teaches others to drive stick and the mechanically inclined friend, I get to drive a varied set of cars.

This Camry smells of gas. I will stand at the exhaust, the exhaust manifold and the fuel filter to see where the smell is from?

 

ok, no codes but what about all 7 systems? are they all 'ready' or are some pending? what about pending trip codes?
tony

 

No pending codes either. Either the OBDII system has been hacked or the car is doing really good.

I was surprised there were no codes on this car either given its age.

I will check the systems.

Will this Techstream dongle be helpful over OBDII: http://www.ebay.com/itm/Mini-VCI-16...-OBD2-Diagnostic-Cable-for-TOYOTA-TIS-Techstream-Cable-CD-US-SHIP-/231271649255

Well if you're smelling raw gas at the tailpipe then the engine is flooding and I doubt will start let alone run. Your exhaust should show black smoke.

Again, check for leak.

Ok. Thank you.

PS: Are people seeing the quotes? I see it in the responses but they don't seem to be rendering in the post. I replied to two people in this post mcgowaw and Stillrunning.

Here is the raw code:

[ QUOTE=mcgowaw;11356394 ]ok, no codes but what about all 7 systems? are they all 'ready' or are some pending? what about pending trip codes?
tony[ /QUOTE ]

No pending codes either. Either the OBDII system has been hacked or the car is doing really good.

I was surprised there were no codes on this car either given its age.

I will check the systems.

Will this Techstream dongle be helpful over OBDII: http://www.ebay.com/itm/Mini-VCI-16...-OBD2-Diagnostic-Cable-for-TOYOTA-TIS-Techstream-Cable-CD-US-SHIP-/231271649255

[ QUOTE=Stillrunning;11356442 ]Well if you're smelling raw gas at the tailpipe then the engine is flooding and I doubt will start let alone run. Your exhaust should show black smoke.

Again, check for leak.[ /QUOTE ]

 

dunno bout the cable you linked to. it might be just a cable for a reader. try this one:
http://www.ebay.com/itm/Car-Diagnos...less-Bluetooth-Code-Reader-/271630341738?hash=item3f3e6e166a:g:ki0AAOSw1x1UNW8B
you do have to have an android device also running the free 'torque' software to talk to it via bluetooth of course.
mine works great. graphs o2 sensors, stft's, 0-60times, temps, codes, system status, closed/open loop, etc.
tony

 

Yes I use that ELM327 reader first thing before I buy any cars. I have Torq Pro.

OBDII is generic and since I see no codes, I was wondering if the Toyota specific cable I linked to would yield better information.

That cable is pretty popular on newer (2014+) Camrys to clone keys and activate OEM alarms, but I am not sure if it's compatible or useful for the 98 I have.