I know this is probably nothing, but after fixing my "dying at stops and turning around' problem by cleaning out the throttle body, I figured I may as well get the rest of the intake cleaned out with seafoam, as there was a lot of carbon buildup in there as well. The only vacuum port that I found was under the vortec engine cover, on the passenger side, half way back. I had to snap the plastic nipple off the end to actually open it up, but thats ok becuase I have a ton of rubber vacuum plugs to cap it off with. I ran a vac line to it, into the seafoam and started it up and of course it smoked like a bitch, like always. When the can was empty I put the vacuum cap on, then noticed the check engine light was on. I figure the o2 sensors didnt like the seafoam so I took it for a drive and ran the piss out of it. Runs great, hauls ass, I just have a damn check engine light on now, which starts blinking off and on while driving. I disconnected the battery for 30 minutes and that didnt clear it, so I guess I need to take it to autozone tomorrow to have it hooked up to a code scanner. I am sure this is nothing but I am wondering if anyone else has done this to their 200k mile tahoe. Anyway I thought I would ask, im not worried about it as i said it runs fine.
Seafoam + Vacuum line = Check Engine light
- Thread starter Chads93GT
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
JKmotorsports
tahoeyukonforum.com
Probably just all the gunk blown onto the upstream O2 sensors. I use the vacuum line from the brake booster with a funnel. Much easier for me and goes evenly to all cylinders thru the intake.
So what do you recommend about the light, just run it till it goes off or goto autozone and have it cleared? Like I said im not really worried about this, I am just wondering. This is just my work vehicle/mobile office, so I don't mod it or anything, thats what my mustangs are for ;D
Gordo
Full Access Member
sounds right from what jkmotorsporst says. I would go to autozone just to make sure if it is your O2 censor then try running one tank of premium fuel from a good gas station like Chevron,Shell or Conoco and 44k to clean your system but you cant find that at autozone you have to go to NAPA or PepBoys or CarQuest try that I know that worked for my 91 cadi'
Well I changed the oil, fuel filter, bla bla today and pulled all 4 o2's. They were relatively clean for.......well.......195k miles. Anyway I cleaned them off, put them back in and still got the flash. I noted that there was a sluggish feeling upon idle when in gear. No biggie, went to autozone....go figure. Misfire in cylinder #5. Well my plug wires were original and the last time I changed the plugs was around......70-80k miles ago so I went ahead and put new plugs in it. Problem solved.
Im a ford guy and the cylinder # order on a smallblock windsor starts on the pass side front to back 1-2-3-4, then drivers side front to back, 5-6-7-8
How is the chevy 5.3 cylinder# order? I am thinking 1 3 5 7, 2 4 6 8, for some reason...... All the plugs actually looked fine but one of them must have been fouled from them massive amount of crap that no doubt was burnt out of the system last night. Anyway hopefully someone reads this in the future after they do this and have a similar problem. Truck runs great again. Thanks for the advice.
Im a ford guy and the cylinder # order on a smallblock windsor starts on the pass side front to back 1-2-3-4, then drivers side front to back, 5-6-7-8
How is the chevy 5.3 cylinder# order? I am thinking 1 3 5 7, 2 4 6 8, for some reason...... All the plugs actually looked fine but one of them must have been fouled from them massive amount of crap that no doubt was burnt out of the system last night. Anyway hopefully someone reads this in the future after they do this and have a similar problem. Truck runs great again. Thanks for the advice.
i did my yukon the way jk did his dumped it in through the boster line while it was runing after was all in shut it of and let sit for bought 1/2 hour and then ran crap out of it didny get a check engine light with the yukon, but did with my moms liberty renagade drove it a lil while then cleared coad and has been all good since
Rivieraracing
Full Access Member
Did you guys put the WHOLE bottle in or the 1/3 of a bottle as written on the bottle?
haha I put in the WHOLLLLLLLLLLLLLE bottle. I read the 1/3 bottle thing and said..........ahhh......200k miles.............it needs extra cleaning 
But it runs great now, tuneup was needed anyhow, but I see what you mean, that full bottle probably fouled the plug.
But it runs great now, tuneup was needed anyhow, but I see what you mean, that full bottle probably fouled the plug.Rivieraracing
Full Access Member
Naw, I was thinking about doing the Seafoam engine cleaning to my Yukon but was thinking about the whole bottle myself. I am a firm believer of more is always better!!!
Rivieraracing
Full Access Member
Thanks for the info, I am probably going to do that this weekend, just cleaned out my throttle body last night so figured I'd do the rest!!
dye4metal
Full Access Member
mine did the same thing after i poured seafoam into it only after 100 miles. i have replaced the intake manifold gasket, plugs, and now im going to replace the evap solenoid on the tank which should hopefully fix the light. i hope yours isnt as bad. my scanner said it wasnt the 02s
Ive already put 700 miles on the tahoe since I put the new plugs in, and ran the sea foam through it 3 days ago. Truck runs fine. I think the evap solenoid and canister went bad on mine about 50k miles ago, i ahd those changed out as well last year
