Catalytic Convertor off, Check Engine Light on?

[Saladin45]

Hey y'all

I've finally sort of nailed all of my issues with this car. Except for this last one.

I pulled the catalytic convertor off, because I thought maybe that it was clogged and causing backpressure up in the motor.

Well, it turns out there's no catalyst in the Catalytic convertor. As I began to start the car without the cat attached, the car sounded fine. It revved ok, held it steady pace, it was fine! Loud, but fine! It even started without any hesitation. (In the past, it would take 2-3 cranks before it would start, without the cat on, it starts with just one turn of the key)

So I reinstall the cat to get an idea of what the hell is going on just to make sure. Well, the engine starts shaking side to side due to the catalytic convertor shifting side to side as well. All of a sudden, maybe five minutes into running, the car starts sounding like it wants to shut off. It starts sorta struggling and immediately I turn the vehicle off.

Well, admist all this, I've got a check engine light on. So I'm thinking to myself, what the heck have I gotten myself into? While the vehicle had its catalytic convertor off as well, the check engine light came on. So is the 02 sensor reading funny due to the fact that the cat is off? Or is there a much more deeper issue at hand here?

I'm fairly positive however that the catalyst in my catalytic convertor has went up into my muffler and pipes. As when they were connected prior to taking off the cat, I was having smoke come out of the vehicle. White, puffy smokey smoke. And after taking the cat off, there wasn't any smoke.

Does anybody have any idea's?

-Saladin

 

[UNGN]

Pull the codes to see what the check engine light is.

If the mufflers aren't clogged (that Would be weird, and almost impossible), I'd go Bad MAF AND bad O2 sensor.

The catalyst in the converter was likely knocked out by a previous owner with a steel rod and very, very, very unlikely fell apart spontaneously and went downstream to clog the exhaust.

 

[Saladin45]

I already put in a new 02 sensor and today installed a new MAF.

And I will hopefully get a neighboor with a scantool to run a test this week/weekend.

 

[salvageV6]

Why wait?

Malfunction Codes Reference

 

[garyk1970]

ive had o2's go bad from the vibration of cutting off exhaust componets near the o2........

 

[Saladin45]

Ok, so I came up with Code 45.

It looks to be the possible causes are...

1) O2 sensor defective or contaminated (if incorrect RTV sealant or too much RTV is used, this may happen)
2) Leaking fuel injectors
3) Fuel pressure too high
4) EMI interference from poor plug wires
5) Evaporative Emission system defect
6) TPS and/or EGR problem
7) MAF sensor reading higher airflow than is actually present


I did it a couple times just to make sure I was doing it right. And I kept coming up with code 45.

I really need to invest in a Scantool. All this counting is... Well it leaves alot of room for human error.

The thing is, I just replaced the 02 sensor.

I do have new injectors, not in yet, but I do have them so I can install those either way.
I replaced the MAF. So that can't be it. The EGR I replaced as well. I didn't really get into the TPS.

But one thing I did notice.

My brother took the catalytic convertor off when I wasn't home, and when I got in, he had the TPS unplugged. Could he have thrown off its setting by unplugging it?

Another question. If it is indeed the injectors leaking, by pulling the spark plugs out and seeing if they are fouled, is that another way to have even more proof that it is them that are the cause? Or no?

 

[garyk1970]

what fpr are you using? pull vacuum line off and look for gas,if so,bad fpr.

a scan tool can tell you what the maf "sees" should be around 4 at idle.

unplug maf and o2 one at a time to see if theres any change. clear the codes after test.

tps should be OK.

you could try after all above to pull injector one at a time to look for any changes....

still sounds like the o2 is bad/contaminated and its not reading the fuel and its telling the computer to dump more in.

 

[Saladin45]

Gah. I just put in that new 02 too... Less than like 2 weeks ago. Then again, it was cheap..

I will try it though.

Also, mind you, this engine is a Hotair engine. So getting to the injectors is a little more... Complicated, let's say, than per say maybe an 86/87.

 

[garyk1970]

Gah. I just put in that new 02 too... Less than like 2 weeks ago. Then again, it was cheap..

I will try it though.

Also, mind you, this engine is a Hotair engine. So getting to the injectors is a little more... Complicated, let's say, than per say maybe an 86/87.

just last week i cut on on exhaust on an toyota and the upstream o2 went south just like that.the vibrattion from the sawsall got it.

 

[Saladin45]

Ah ok. Gotcha.

But here's a question.

Why is it that I didn't get any smoke once I took the cat off then? It sounded like a fine running machine once it was off. It didn't stumble under acceleration (As it has been) and there was no white smoke.