Still popping thru exhaust

[Redog]

OK I got the headers fixed, the gaskets needed to be replaced. The car responses better but still stumbles and pops out the exhaust when I get on it. In fact, it's now doing it on a cold engine with normal driving.

I'mgoing to test the MAAF wires in the morning, but I doubt that's the problem. My WB AF ratio will drop to 10.1 when I get on it and jumps up in the 14's when it pops (I'll check again tomorrow, not a def number) and when I get off it and hit the brakes it goes as high as 17.4, although over the past few days it's only going as high as high 15's

I think it's a tuning thing, any ideas?

[Redog]

Anybody on here know?

I posted this question on 60degreeV6.com and also no answers. I know somebody knows this

[[ion] C2]

You're talking when you get off it right, not on. Under decel (no throttle) it pops?

[a.graham52]

hows your fuel trim numbers? 10.1 sounds a little rich to me. and when you let off getting 15.1 sounds like its running lean. might be a trim issue. do you have any missfires? how about a dead 02 sensor? maybe its within spec but maybe not fluctuating properly.

[[ion] C2]

10.1 is too rich under throttle (assuming it stays around there and isn't just a momentary thing).

Under decel it's not toooooo critical what the AFR is. I suck at tuning decel.

[a.graham52]

well if your too lean under decel thne you will get a poping noise. out the exhaust.

[Redog]

No it's popping under accel and yeah it goes to between 10.1 and 11.2

decel it's fine

[a.graham52]

you never awnsered. does it have a missfire at all? that could account for the rich mixture.

[[ion] C2]

too rich for sure. weird, usually modded cars get leaner.

[a.graham52]

you never awnsered. does it have a missfire at all? that could account for the rich mixture.

gotta check that.

[Redog]

Yeah it misses

[robalero]

clogged cat? is it glowing red hot when this happens?

[a.graham52]

how are your plugs and wires? check them, they could be fouled or arcing or the plug could be cracked. start with the basic. what cylinders are missing? could they be sharing a coilpack?

[robalero]

I personally think its the cat, ill wait to hear back and you tell me if its glowing red hot

[Redog]

Cat is fine

I was cleaning under the hood today and I know 2,4,and 6 the wires are fine, IDK about 1,3,or 5. I also know the porclien (sp) parts or 2,4, and 6 and also fine.

I'll pull the plugs tomorrow (at work right now)

[a.graham52]

do you have a scan tool or something that will tell you exactly what cylinders are missing?

[Redog]

My scanner will only scan an actual SES light.

Do you think Advanced Auto or Auto Zone could scan for that?

The plugs aren't that old. I replaced them last May when I popped one out of the head. I also used my circut tester on the MAF connection today, and they both checked out. The one was dim, so I opened the throttle a bit and the car just died :lol:

[a.graham52]

i dont think so. you could stop by a dealer and see if they would just hook up a scan tool and look at your history missfires for free. once in a while we do that for customers.

[[ion] C2]

I've found the misfire logs to be misleading. Same with the "Current Misfires" PID. Inconsistent data with the actual problem.

[Redog]

Hmmmm, What should I do :drunk:

[a.graham52]

iv never had issues distinguishing history missfires. if you ahve a cylinder with 11xxx missfires and one with 5xxx misses... go for the higher number. theres a logical reason why it does that but i cant remeber what iwas told.

[xXManwhoreXx]

Fixed yet? Its definately not the exhaust.... Thats a terrible idea. My guess is either ignition or something fuel wise. no cel's at all?

[Redog]

No SES, it's tuning issues. I figured it out to that point.

[xXManwhoreXx]

To much fuel or ignition to advanced?

[[ion] C2]

The question is, when exactly did this begin? What changed on your car before this started happening?

Get it to ASS and I'll check it out. Well I'm sure everyone will but I'd like to look at it for sure.

[Redog]

It's been having these issues since July, but it was very random, it's just getting more often.

July I had a head gasket issue and it was fixed with new heads that I bought off Fuller

[[ion] C2]

you have hptuners, load up a datalog for me so we can see what's up

[Redog]

At work, don't have my laptop.

I'll run a fresh one tomorrow and send it to you ;)

[Redog]

Well I got on it today and paid close attention to the WB and when it was popping it shot right to 17.2 and up to that it was hanging out about 13.9 to 15.4 which is high for WOT

Caught all this on a HPTuners scan

[AleroB888]

Well I got on it today and paid close attention to the WB and when it was popping it shot right to 17.2 and up to that it was hanging out about 13.9 to 15.4 which is high for WOT

Caught all this on a HPTuners scan

I have not read this whole thread, but can you watch the fuel pressure reading at the exact time this happens?

[[ion] C2]

Mine used to get lean spikes and it was due to the TPS. Hopefully whatever it is is obvious in the log.


You already disconnected electrically the upstream O2 sensors right? No change?

[Redog]

No I didn't do that :drunk: