check engine light code P0172

angelglo · Post by **angelglo** » 28 Feb 2006, 13:30

i have my 97 GLT volvo running pretty smooth with a 98 v70 motor w/turbo. i replaced it about 1 month ago. i am getting engine codes P0172, P0300, P0301, P0302, P0303, P0304 and P0305. i looked them up and it is running rich with misfires in the cylinders. i clear the codes after installing new plugs, wires, cap and rotor and the lights codes still pop up. sometimes its only a misfire in some of the cylinders andsometimes its all the cylinders.

can someone give me any guidance regarding what might be the problem. i also need to mention that i changed the timing belt but im poitive that i lilned up the markings correctly. i would like to try and solve this without taking it to the dealer.

thanks
angel

Tsquared · Post by **Tsquared** » 28 Feb 2006, 16:56

P0172 - Recently had this, I replaced the O2 sensors and it turned out to be a rotted vacume elbow, could also be ETC coolant temp sensor, MAF, leaking fuel injectors (air leak - not fuel), low fuel pressure, PCV system problems, leaking oil cap gasket, or exhaust leak near the O2 sensors... see: https://www.matthewsvolvosite.com/chat/p ... php?t=6283

P0300 - possible problems include Camshaft sensor (CMP) or Stuck open EGR valve - The PCM cannot ID misfiring cylinder.
p0301-0305 - Ignition system, Low fuel pressure, EVAP canister purge valve, Evap emisions system problems

Hope this gets you looking in the right areas,

T2

angelglo · Post by **angelglo** » 09 Mar 2006, 17:00

ok,

i took my 850 glt into the shop to get a diagnostic. they told me that the O2 sensors were bad along the the cat converter. they also mentioned that the air mass sensor was also probably bad. it was also mentioned that some vacuum lines might be bad or crossed which i dont think are crossed. i will start looking at the O2 sensors and replacing them. the dealer is charging 236 a piece for the front and back. i think i found some universal ones at kragen.com for cheaper. should i buy the one at kragen, dealer or one of the sponsers of this site. im sure you guys will point to the sponser but the one at kragen is alot more convienent. also i will be buying a ct converter. i found one on ebay. here it is. if posting this is a no no, please remove.

http://cgi.ebay.com/ebaymotors/Volvo-19 ... dZViewItem

would this one be ok to buy and install? i know there are cats for OBDii so i was wondering if this would comply.

anyway, that is where i will be starting. hopefully i get it solved. i dont want to be driving with the check engine light on all the time plus i know the rich condition will again screw up my cat.

angel

Post by **MadeInJapan** » 09 Mar 2006, 17:26

Save yourself the headache of looking for the 02 sensors and just go to www.fcpgroton.com All the parts you mention can ge acquired there...however I would not buy the CAT from there if you're really replacing that. I'd go with a Magnaflow or the one that you linked to above...doesn't seem to really matter (good price on that one above!) Those on www.volvospeed.com are posting that with the magnaflow they are still passing emmissions testing with flying colors.

I'm wondering however if you should get a second opinion. It's hard to imagine that all of those parts are going at the same time. One can cause codes in the others....especially the MAF. BTW, sometimes these are on eBay too for a savings. All 850's w/turbo use the same one.
Good luck!

angelglo · Post by **angelglo** » 09 Mar 2006, 18:38

is there a diffence between an OBD11 cat and a regular cat?

thanks
angel

Post by **MadeInJapan** » 09 Mar 2006, 20:57

From what I understand a CAT is basically a CAT. Current day ones typically have a 3 layer design that absorb all of the heavy metals, etc. that pass through. The issue with the CAT is diagnosed by the OBDII scan tool by reading the difference between the O2 sensor before and after the CAT. Thus, many times, the CAT isn't the issue at all, but one or both O2 sensors that are fouling up, or even the MAF, or vacuum leaks or a number of other issues. That's why I mentioned that I would be suspicious of all of these things going bad at once. Get a second opinion.

warrenjoel · Post by **warrenjoel** » 10 Nov 2006, 13:51

My 1999 V70 XC Turbo started running poorly, and quickly deteriorated. Engine light signaled diagnosis with OBD II said cyliner five problem. It turned out to be coil failure, not plug, injector, etc. It work fine now.